UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Productivity : state-of-the-art, recording context information, and case study data sets Dimitrijevic, Marina 2001

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-ubc_2001-0182.pdf [ 34.32MB ]
Metadata
JSON: 831-1.0063989.json
JSON-LD: 831-1.0063989-ld.json
RDF/XML (Pretty): 831-1.0063989-rdf.xml
RDF/JSON: 831-1.0063989-rdf.json
Turtle: 831-1.0063989-turtle.txt
N-Triples: 831-1.0063989-rdf-ntriples.txt
Original Record: 831-1.0063989-source.json
Full Text
831-1.0063989-fulltext.txt
Citation
831-1.0063989.ris

Full Text

PRODUCTIVITY: STATE-OF-THE-ART, RECORDING CONTEXT INFORMATION, AND CASE STUDY DATA SETS by MARINA DIMITRIJEVIC B.A.Sc, The University of Zagreb, 1987 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE FACULTY OF GRADUATE STUDIES Department of Civil Engineering We accept this thesis as conforming .Jertrje required standard THE UNIVERSITY OF BRITISH COLUMBIA April, 2001 © Marina Dimitrijevic, 2001 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of ^ t ^ L (r7J&1 fj £££ I A> Q-The University of British Columbia Vancouver, Canada Date £ g , ^ 1 DE-6 (2/88) Abstract The goal of this thesis is to contribute to our understanding of construction productivity as a function of methods employed and site conditions encountered for activities such as: excavation, shoring, and forming and concrete placing activities (column footings, columns, walls, and slabs). This goal has been pursued through three objectives: A comprehensive literature search about construction productivity to determine the state-of-the-art of predictive relationships as a function of factors that influence productivity. The major finding is that there is no unique and universal relationship that can be used to predict construction productivity. The carrying out of a detailed case study in order to develop comprehensive data sets for the construction of different elements, recording of the methods used, problems encountered, etc. The case study consisted of a detailed day-to-day data collection for the first 20-week period of the construction at the Kerrisdale Station Project in Vancouver. The testing of a daily site reporting system in order to assist in its development and enhancement for use in project monitoring. A research system called REPCON5, a project scheduling and site reporting system, was chosen as the tool for the collection of the daily events at the site. The daily reporting module allowed recording of construction activities, site condition, environment data, on-site equipment and usage, job-site visitors, inspections, meetings, problems encountered, etc. Findings from the work performed should be of value, to other researchers in their quest for forecasting productivity as a function of various factors that have an impact on construction productivity. TABLE OF CONTENTS Abstract ii Table of Contents iii List of Tables iv List of Figures V Acknowledgment vii Chapter 1 1 Introduction 1 1.1 Objectives 1 1.2 Overview of Thesis 4 Chapter 2 6 Literature: State of the Art 6 2.1 Productivity: Definition, Factors and Modelling 6 2.2 Loss of Productivity and Delay Claims 10 2.3 Productivity Improvement 11 2.4 Monitoring and Reporting 13 2.5 Analysis of the Construction Productivity Literature 15 Chapter 3 68 Kerrisdale Project and Site Documentation 68 3.1 Case Study Background Information 68 3.2 Documentation of Site-Activities 85 Chapter 4 85 Use and Refinement of a Computer Based Tool for Monitoring the Construction Process 85 4.1 Planning for the Case Study Project 85 4.2 Updating 93 4.3 Monitoring 96 4.4 Reporting and Data Representation 109 4.5 Enhancements to the Daily Site System 126 Chapter 5 130 Case Study Activity Data 130 5.1 Excavation 131 5.2 Shoring 139 5.3 Concrete Construction 157 Chapter 6 184 Conclusions and Recommendations 184 6.1 Conclusions 184 6.2 Recommendations 185 References 186 Appendix 1 194 Appendix 2 208 Appendix 3 220 LIST OF TABLES Table 2.6.1 Analysis of Construction Productivity Related Papers 17 Table 4.2.1 Duration for Various Numbers of Planned Stages and Different Update Dates 95 Table 4.3.1 Problem Categories and Description 106 Table 4.4.1 The List of Problems Marked During the Daily Site Recording in Period From 23/June/1999 to 5/November/1999 111 Table 4.4.2 Excerpt From the REPCON5 Daily Site Problem Sources Report 113 Table 4.4.3 Excerpt from Work Environment Daily Site Report 117 Table 4.4.4 Excerpt From the REPCON5 Work Force Report 120 Table 4.4.5 Canadian Climate Normals 1961-1990 VANCOUVER INT'L A, British Columbia, 49°11-N 123°10-W/O 3m 1937 to 1990 122 Table 4.4.6 A Guide to Summer Comfort 123 Table 4.4.7 Humidex for the Range of Different Temperature and Humidity 123 Table 5.1.1 Quantity Takeoffs for Excavation 131 Table 5.2.1 Shoring Quantity Takeoff Data 143 Table 5.2.2 Production Rates and Productivities of JJBO Soil Anchors Installation in the Kerrisdale Station Project 145 Table 5.2.3 Production Rates and Productivities of DYWIDAG Soil Anchor Installation 146 Table 5.2.4 (a) Production Rates and Productivity of Sand Trimming 148 Table 5.2.4 (b) Production Rates and Productivity of Wet Clay Trimming 148 Table 5.2.5 Production Rates and Productivities of Soil Removal 150 Table 5.2.6 Production Rates and Productivities of Shoring Panel Reinforcement 152 Table 5.2.7 Production Rates and Productivities of Shotcreting 154 Table 5.2.8 Cycle Time Record, Production Rates and Productivities of Anchor Tensioning 156 Table 5.3.1 Summary of Crane Usage 158 Table 5.3.2 Quantities, Production Rates and Productivities of Footing Formwork, Concrete Placement and Stripping 160 Table 5.3.3 Quantities, Production Rates and Productivities of Column Formwork, Concrete Placement, and Stripping 168 Table 5.3.4 Quantities, Production Rates and Productivities of Wall Formwork, Concrete Placement and Stripping 172 Table 5.3.5 Quantities, Production Rates and Productivities for Slab on Grade and Suspended Slab Concrete Placement 177 iv LIST OF FIGURES Figure 2.6.1 Source of Articles Included in the Literature Research 16 Figure 2.6.2 Type of Data Collected re Type of Project 59 Figure 2.6.3 Type of Data re Monitored Activity 60 Figure 2.6.4 Productivity Issues 61 Figure 2.6.5 Monitoring Method 62 Figure 2.6.6 Transferability 63 Figure 2.6.7 Qualitative vs. Quantitative Analysis 64 Figure 2.6.8 Predictive Relationship 65 Figure 3.1.1. Mock-up of the Kerrisdale Station Project 69 Figure 3.2.1 Example of the General Contractor's Daily Diary 73 Figure 3.2.2 (a) The REPCON5 Daily Site Form - General Project Data and Activity Information 75 Figure 3.2.2 (b) The REPCON5 Daily Site Form - General Project Data and Activity Information 76 Figure 3.2.2 (c) The REPCON5 Daily Site Form - General Project Data and Activity Information 77 Figure 3.2.2 (d) The REPCON5 Daily Site Form - General Project Data and Activity Information 78 Figure 4.1.1 As-Planned Schedule with Seven Stages Updated on 23-June-1999 87 Figure 4.1.2 The Definition of the 7-Stage Strategy. Drawing not to Scale 88 Figure 4.1.3 Excerpt from a Preconstruction Master Schedule Made by Construction Management Company 88 Figure 4.1.4 Hand-Drawn Schedule Made in Mid September 1999 by the General Contractor's Superintendent 90 Figure 4.1.5 Schedule Made in November 1999 (the First of Three-Page Schedule) by the Forming and Concrete Placing Subcontractor's Superintendent 91 Figure 4.2.1 Construction Schedule Updated as of August 31,1999 94 Figure 4.3.1 REPCON5 Daily Data Report Sheet 97 Figure 4.3.2 REPCON5 Site Conditions Window 99 Figure 4.3.3 REPCON5 Work Force Window 101 Figure 4.3.4 REPCON5 Survey Works Window 102 Figure 4.3.5 REPCON5 Inspection Window 103 Figure 4.3.6 REPCON5 Deliveries Window 104 Figure 4.3.7 REPCON5 Daily Status Data - Work Force 107 Figure 4.3.8 REPCON5 Daily Activity Status Data - Equipment 108 Figure 4.4.1 Status of the Bulk Excavation on West Side Activity 110 Figure 4.4.2 Problem Status by Problem Code and Location for All Activities 112 Figure 4.4.3 Number of Problems, Total Manhours and Time Lost for the Whole Project 114 Figure 4.4.4 Problem Status for Poor Ground Conditions for Excavation and Shoring Activities 115 Figure 4.4.5 Precipitation, Temperature, and Wind Speed vs. Time 116 Figure 4.4.6 (a) Work Force for Whole Project 118 Figure 4.4.6 (b) Work Force for Formwork Trade 118 Figure 4.4.7 Number of Wind-Too-Strong Problems Occurred in Period From June 23 to November 5 121 Figure 4.4.8 Number of Congestion Problems for All Activities in the Period from June 23 to November 5 125 LIST OF FIGURES (continued) Figure 5.1.1 Excavator Performance Sheet for 25-June-1999 134 Figure 5.1.2 Comparison of Actual and Standard Cycle Times for Sandy Conditions by 330-B CAT Excavator on 21 July 1999 135 Figure 5.1.3 Daily Excavation Production and Comparison with Standard Rates 136 Figure 5.1.4 Excavation (CAT 33OB and Tandem Dump Truck 137 Figure 5.1.5 Poor Ground Conditions (Hard Clay) and Ground Water During Excavation 137 Figure 5.1.6 Sump Pump to Remove Excessive Water 138 Figure 5.2.1 (a) Trimming Soil for Shotcrete Panel 140 Figure 5.2.1 (b) Drilling for Anchor 140 Figure 5.2.1(c) Panel Reinforcement 141 Figure 5.2.1 (d) Shotcreting 141 Figure 5.2.1 (e) Grouting the Anchor 142 Figure 5.2.1 (f) Anchor Tensioning 142 Figure 5.3.1 (a) Excavation for Footing 161 Figure 5.3.1 (b) Compaction of Excavated Footing Bottom 161 Figure 5.3.1 (c) Installing Footing Formwork 162 Figure 5.3.1 (d) Footing Reinforcement 162 Figure 5.3.1 (e) Placing Footing Concrete Pouring 163 Figure 5.3.1 (f) Vibrating the Footing Concrete 163 Figure 5.3.1 (g) Footing Concrete Finishing 164 Figure 5.3.2 (a) Installing Strip Footing for Perimeter Walls 165 Figure 5.3.2 (b) Installing Strip Footing Reinforcement 165 Figure 5.3.2 (c) Placing Perimeter Strip Footing Concrete 166 Figure 5.3.2 (d) Perimeter Strip Footing Finished and Stripped 166 Figure 5.3.3 Excessive Ground Water in Hole Excavated for Footing 167 Figure 5.3.4 (a) Column Forms Arrive on Site 169 Figure 5.3.4 (b) Installing Column Reinforcement Cage 169 Figure 5.3.4(c) Installing Column Form 170 Figure 5.3.4 (d) Placing Column Concrete 170 Figure 5.3.4 (e) Finished and Stripped Columns 171 Figure 5.3.5 (a) Storing Wall Forms 173 Figure 5.3.5 (b) Installing Wall Formwork 173 Figure 5.3.5 (c) Installing Wall Reinforcing 174 Figure 5.3.5 (d) Placing Wall Concrete 174 Figure 5.3.6 Rework Required due to Formwork Failure 175 Figure 5.3.7 (a) Preparation for Slab on Grade (Stone Slinger Fills in Slab on Grade Foundation with Gravel) 178 Figure 5.3.7 (b) Preparation for Slab on Grade (Compaction of Gravel Foundation) 178 Figure 5.3.7 (c) Placing Slab on Grade Concrete with a Concrete Pump 179 Figure 5.3.7 (d) Finishing Slab on Grade 179 Figure 5.3.8 (a) Receipt of Shoring Frames 181 Figure 5.3.8 (b) Assembling Shoring 181 Figure 5.3.8 (c) Attaching Beam Supports 182 Figure 5.3.8 (d) Erecting Support Beams 182 Figure 5.3.8 (e) Placing 4x6 Cross Support Members 183 Figure 5.3.8 (f) Placing Plywood Sheeting 183 vi A C K N O W L E D G M E N T I would like to express my appreciation to my supervisor, Dr. Alan D. Russell, for invaluable advice, guidance and encouragement throughout the studies. Without his support and optimism, this work would not have been possible. I also greatly appreciate Dr. Thomas Froese's valuable suggestions that improved the thesis' content. Well-deserved thank-you to the Intertech Construction Managers Ltd personnel: Mr. Harold Barisoff, project manager, Mr. Ken Reeve, site superintendent and Mr. Sten Carlson, P.Eng., site superintendent, for accommodating my colleagues and me on their project and providing us with a clearer understanding of the construction and project management approach. A special thank-you is aimed to Mr. Bill lies from HP Builders Ltd, the forming and concrete placing subcontractor superintendent for his time to explain the management strategy. A colleague and dear friend of mine Sanjaya de Zoysa shared his experience, helping me understand the winding path toward graduating. A very special place in the acknowledgment note is reserved to my parents Marija and Miroljub Dimitrijevic and sister Mira Jovicic and her family for their unconditional encouragement and support throughout the tough period of my newcomer's homesickness. And finally to my husband Goran Sreckovic, who, as a grad student at the time, understood all the phases I was going through, trying to make them as painless as possible. vii Chapter 1 Introduction 1.1 Objectives The purpose of this thesis was to make a contribution to our understanding of productivity as a function of site condition and methods. Specific thesis objectives for this thesis are: To determine the current state of our knowledge in relation to predicting and/or explaining productivity as a function of a diverse range of factors; To contribute to the design and evaluation of a computer-based tool for collecting as-built project information that can be used to help to explain productivity levels achieved, and To collect data sets from an actual project for use by other researchers working on the topic of productivity. Various samples of data are used to demonstrate the breadth and depth of the data collected and how they can be analysed. The methodology for the first research objective consisted of a thorough literature search to develop an appreciation of current views on construction management documentation and pertinent aspects of project monitoring and construction productivity. This was carried out by browsing through the University of British Columbia Library and by browsing through the Internet. Literature sources were found at the University of British Columbia's Main and Law Libraries, the Central Branch of the Vancouver Public Library, and the Library at Simon Fraser University. 1 The following web addresses were found to be very useful: http://toby.library.ubc.ca/ejournals/ejournals.cfm - UBC library resources - Electronic Journals http://toby.library.ubc.ca/resources/catlist.cfm -UBC Library Resources Other Catalogues http://wos.isiglobalnet.com/ - Web of Science http:// silverpl after, library.ubc. ca/cgi-bin/webspirs.cgi?sp.dbid.p=COMP5A&sp.dbid.p.=COMP5B&sp.dbid.p.=COMP5C&s p.dbid.p=COMP006A&sp.dbid.p.=COMP008A&sp.dbid.p.=COMP0037&sp.nextform =search.htm - WebSPIRS Search - COMPENDEX http://silverplatter.library.ubc.ca/cgi-bin/webspirs.cgi - WebSPIRS - Database Selection http://hilltop.bradley.edu/~jadrian/ - Dr Adrian's Construction Education and Training Online http://www.abuildnet.com/texis/db/buildsearch/ - BuildNET Construction and Building Search Engine http://weather, ec. gc. ca/forecast/yvr.html - Environment Canada Weather Forecast for Vancouver http ://www.interlog. com/~keobrien/ AboutKerry.html - Construction Productivity Improvement, Kerry OBrien http://construction-institute.org/ - Construction Industry Institute http://www.leanconstruction.org/DBIAPlen/sld001.htm- Keys to Better Productivity for Design and Construction, Gregory A. Howell, P.E. http://www.projectmgmt.com/CP.HTM - Construction Productivity. "A Measurement of Worker Efficiency? " By. Robert L. Ryser, BSME, MBA, P.E. 2 http://asc.editor.unl.edu/archives/construcl.htm - Construction Productivity Improvement, Gouranga C. Banik, Southern Polytechnic State University, Marietta, Georgia http://www.brtable.org/document.cfm/156 - the Business Roundtable - Scheduled Overtime Effect on Construction Projects One of the goals for the second research objective was to build a detailed daily site record obtained from a construction project in Vancouver during a 20-week period in order to show what improvements could be made in the data collection strategy and daily site data collection system used. For this purpose, various data collection methodologies described in the literature and their effectiveness in the field were explored in order: (1) to identify how difficult it is to get accurate, detailed data; (2) to describe the realities that surround the execution of everyday construction projects; (3) to determine the causes of schedule delays; (4) to assess the impact of weather and site conditions on activity progress; and (5) to assess the impact of encountered problems. A key part of the methodology used for this objective consisted of the use of a research system called REPC0N5 (Russell, 1993), a project scheduling and site reporting system. The daily reporting module allows recording of construction activities, site conditions, environment data, on-site equipment and usage, job-site visitors, inspections, meetings, problems encountered, etc. For the third objective of this thesis, a case study was carried out on the Kerrisdale Station Project in Vancouver. The Project is a mixed use one, consisting of a commercial and residential facility combining concrete and wood frame construction. A total of six graduate students in construction engineering and management observed the project over a 20-week period (June 1999 - November 1999). This work was divided into two phases. Phase one ran from the start of excavation in June until the end of August, and involved four students focusing on bulk excavation and shoring (a shotcrete system comprised of anchors and reinforced shotcrete panels). The second phase started in September and ended in November. In this phase, completion of excavation (bulk and detailed) and the construction of the substructure were monitored. The second phase also involved four students. For the substructure, emphasis was placed on forming, concrete placement and finishing activities for footings, columns, walls, cores and slabs. For both phases, at least two students were present on the site for at least half of each workday (except Saturdays). A third phase was added following the second phase and involved only the author of the thesis. This phase of the work focused on tracking construction progress by attending weekly trade meetings and taking pictures of the construction progress twice a week until the end of March 2000. Elements of the data collection methodology used for the second and third objectives are described in section 3.2.2 Data Collection Methods and Techniques. 1.2 Overview of Thesis Chapter 2 provides the findings of a detailed literature review related to construction productivity. Results are set out in a table that views the relevant issues of pertinent papers published in the last 25 years. Besides basic information such as the paper title, its author(s) and a year of publication, the following data were found to be relevant for the appraisal of the literature about the construction productivity research: type of data collected; productivity related issues (weather, accessibility, change orders, etc.); monitoring method; transferability; qualitative vs. quantitative analysis; predictive relationships; and threshold (threshold was used to describe the starting point of an experience of discovering new, or the further developing of 4 the existing knowledge pertinent construction productivity). Findings from the literature review are analyzed at the end of Chapter 2. Chapter 3 describes features of the case study project and research methodology. The documentation of site activities in the form of daily reports prepared by the contractor (Intertech) and UBC study team are described. Data collection methods and techniques used by researchers are described and difficulties in getting accurate, detailed data are identified. Chapter 4 shows the features of the daily site data collection system directed at the as-built view of a project. Contributions to the evaluation and enhancement of the design of this system are described, along with the reasoning behind the changes. Chapter 5 presents many of the findings from the case study, and makes use on a selection basis of data collected by all of the students who participated in the case study. The data collected should be helpful for other researchers working on the topic of productivity. Chapter 6 concludes the thesis and treats future recommendations for enhancement of the capabilities of the research daily site data collection module as well as suggestions regarding data collection methodologies for use in the field. 5 Chapter 2 Literature: State of the Art The intention of carrying out a thorough literature search was to compile what we know about factors that influence productivity, and what definitive predictive relationships exist, if any, that can be used to predict or explain productivity as a function of these factors. Results of the literature search are first treated in sections 2.1, 2.2, 2.3, 2.4, and 2.5, and then findings from what appeared to be the most significant papers are summarized in a table. 2.1 Productivity: Definition, Factors and Modelling Productivity, or the lack of it is perhaps the number one problem confronting the construction industry, the construction firm, and the construction project. It can be viewed as the efficiency with which materials are placed by labour and/or equipment. Productivity is commonly measured by means of the following definition. . . . Units of Output Pr oductivity = =^-= (2.1) Manhours of _ Input or _ Effort According to the Construction Industry Institute's (CII's) definition, productivity is "the input divided by the output" (Chang, 1991). Interestingly, this definition differs from that of the Business Roundtable (BRT) where the productivity is defined as "output divided by input" (Chang, 1991). 6 Finke (1998) defined productivity in terms of workhours per percentage point of completion or progress, per dollar of earned value, or per quantity installed. Construction productivity is an attempt to measure worker efficiency. Ryser (1999) defines cumulative construction productivity as a unitless ratio of man-hours spent to date divided by man-hours earned to date. This definition of productivity indicates that a productivity number that is less than one is an indicator of good efficiency, and productivity number that is higher that one would indicate inefficiency. Drewin (1982) emphasised the difference between the terms productivity and production. Production helps the contractor figure out how long it takes to complete a unit of work. Productivity is not equivalent to performance. Total production, however, can be increased with an increase in any one of the input factors, while, at the same time, productivity may decrease. There is a significant body of research aimed at identifying the most significant factors that affect construction productivity. Important examples include the following. A study group (Fazio et al, 1984) identified the main factors that improve or worsen the levels of productivity in the construction industry in Canada. The factors were grouped into 7 categories: (1) Project conditions, (2) Market conditions, (3) Design and procurement, (4) Management of the construction phase, (5) Labour, (6) Government policy and regulation, and (7) Education and training. Construction industry organizations in Canada responded to the survey, and the labour category factors were singled out as the most important ones. Russell (1993) focused on data collection for factors that affected productivity on a daily basis. The investigation developed data collection procedures based on a superintendent's daily site-reporting diary. Information collected included: (1) weather; (2) site conditions; and problems related to: (3) owner/consultants; (4) design/drawings; (5) work force; (6) rework; (7) insufficient materials/equipment; (8) schedule; (9) utilities/city; and (10) miscellaneous items 7 (e.g., theft, strikes, vandalism, shutdowns). No indication was made on which piece of information was the most significant factor that affected productivity. Besides management factors, labour productivity can be impaired by numerous other factors including disruptions to the work (Thomas and Zavrski, 1999), changes (Thomas and Napolitan, 1995) and unfavourable weather conditions (Thomas, Riley, and Sanvido, 1999; Koehn and Brown, 1985). Little quantitative information has been documented in the literature about the impact of these factors on productivity. Hanna (1994) also identified the types of factors that influence construction productivity. They were classified into six groups: (1) contract environment, (2) planning, (3) site management, (4) working conditions, (5) working hours, and (6) motivation. Ryser (1999) emphasized the importance of accurate project scope definition and described the adverse correlation between the expanded project scope and productivity. Many articles describe change orders and productivity, but few quantify the impact that change orders have on productivity, i.e. the literature on change orders is mostly qualitative. The two published quantitative methods of Moselhi et al. (1991) and Ibbs (1997), however, show a linear relation between the percentage loss in productivity and percentage of change orders that occurs during detailed design and construction, in particular the size of change and its impact on the project. They simply indicate that the more change that occurs in the project original scope, the higher the loss in productivity and accordingly the higher the impact cost of these changes. An attempt to quantify the effects of construction changes on labour productivity was done by Thomas and Napolitan (1995). The results of their study showed that, while in many instances changes did not affect labour productivity, on average, a 30 percent loss in efficiency occurred during the performance of change-order work. 8 Another quantitative approach of the impact of change orders on productivity is the work of Hanna et al (2000), which developed a statistical model that estimates the actual amount of labour efficiency lost due to change orders. Other research has indicated that there is a direct correlation between an increase in change orders and a loss of productivity. One study (Moselhi et al, 1991) reported losses in productivity associated with change orders, combined with other causes of disruption. An interesting finding is that losses in productivity as a result of change orders are not affected by the type of construction, i.e., general building versus industrial projects (Hanna et al, 1998). Productivity-related costs result from productivity losses from the level that could have been achieved on the original scope of work. Unlike time-related costs, productivity related costs can rarely be estimated accurately simply because it is difficult to demonstrate what costs would have been incurred without the adverse effect of changes (Moselhi, 1998). Over the years, numerous scholars and practitioners have developed various models of construction productivity. Some of the more well known models include the factor model of construction productivity (Thomas and Sakarcan, 1994) which concentrates on the specific factors that cause variances in productivity. These factors are defined through two categories: work environment and work to be done. The work environment category relates to congestion, sequencing, weather, supervision, plant status, information, equipment, tools, materials, and rework factors. The "work to be done" category consists of size of components, specification and quality requirement, work content design features, and work scope factors. How each of the factors identified under these categories can be meamngfully quantified is most discussed. Another model of construction productivity is the hierarchy model (Kellogg et al, 1981). It provides a more conceptual framework within which productivity can be analysed. Maloney and McFillen (1985) developed a model of construction worker motivation, performance, and satisfaction, based on expectancy theory. Additionally, a number of work-study based 9 productivity models have been developed, including the delay model, the activity model, and the task model (Thomas, 1990). The same author (1990) developed two reliable productivity models validated specifically for construction. These were the factor model, which accounted for project, site, and management factors affecting productivity, and the expectancy model of motivation. Thomas suggested that the models could be integrated into a single comprehensive model to quantify the factors affecting productivity and to forecast construction productivity, but seemingly this has not been done. Larew (1996) presented a productivity model that depicts the relationship between the quantity to be performed and work-hours required. It can be used to prepare cost estimates, as well as for the starting point for establishing a reliable baseline for calculating the impacts of changes. The current state-of -the-art related to identifying factors affecting productivity in construction is generally inconclusive. Although many factors have been identified, the question of how these factors specifically combine to affect productivity in a given situation is still not clear. 2.2 Loss of Productivity and Delay Claims Numerous identifiable impacts described in the literature affect contractors and can cause a loss of productivity. Recently, the majority of the literature on construction claims has focused on the liability issue. The task of calculating and proving damages for loss of productivity represents one of the most difficult problems in construction claims (Allen, 1995; Baki, 1999). The most widely used methods by contractors in pricing the impact of lost productivity through construction claims are the total cost method and the modified total cost approach (CLL, 1997). The comparison of productivity levels is also referred to as the cause-and-effect method, which requires detailed, 10 accurate and proper documentation to produce meaningful and reliable results for estimating loss of productivity (Kallo, 1996). The measured mile approach for estimating loss of productivity quantifies disruption by comparing the (allegedly) impacted or disrupted productivity rate to a (presumably) unimpacted productivity rate (Zink, 1990; Finke, 1998;). Various techniques have been developed to analyse delay claims. Some of the most commonly used techniques are (Kartam, 1999): what-if evaluations, but-for schedules, collapsed as-built analysis, impacted baseline schedules, after-the-fact and modified CPM schedule, and dollar-to-time relationship. Kartam (1999) developes the Contemporaneous Period Analysis Technique which uses the schedule update for a period as a basis for analysing delays encountered in that period. There is unanimity in the literature as to the advantages to be gained from better insight into change order analysis (Thomas and Napolitan, 1995; Ibbs, 1997) and on-site progress tracking in support of construction claims (Jergeas, and Hartman, 1994; Bubbers, 1992; Semple, 1994; Knoke, 1995; Vanegas and Halpin, 1992, Kallo, 1996; Finke, 1998; Baki, 1999; Dieterle, and DeStephanis, 1992; Zack, 1997). In recent years, based on the settlements being reached, contractors have become increasingly concerned with claims and their associated costs, and the contractors' inability to recover actual costs 2.3 Productivity Improvement Prior to 1970, the main methods construction companies had to improve site productivity consisted of redesigning management systems and organisational structure on poor projects and/or replacing management personnel. In the early 1970s, the modern Productivity Improvement Program (PIP) evolved as another method to improve productivity (Sanvido, 1988). A PJJP is defined as a formalised program for improving the productivity of a project by 11 enhancing the information flow, feedback and resource supply systems, and improving the construction methods and planning function. These PIPs were typically implemented on projects that were 50-80% complete, and that were behind schedule and over budget (Sanvido, 1988). Most of these methods for improvement of productivity are expected to be directly implemented at the construction site as well as the home office. Maloney (1985) emphasized that labour has a significant influence on construction productivity improvement. The level of productivity is a result of the driving, induced, and restraining forces acting upon workers. Arditi (1985) indicated that immediate research for productivity improvement should concentrate on improving marketing practices, planning and scheduling, labour-management relations, site supervision, industrialised building systems, equipment policy, and engineering design. This have led to a search for better marketing practices in the construction industry for productivity improvement. Adrian (1987) recommended eight ways to improve productivity: 1. Better combinations of equipment and labour, 2. Use more efficient equipment and tools, 3. Use better materials, 4. Improve production management, 5. Control an adverse physical environment, 6. Expend greater labour effort, 7. Improve training of labour force, and 8. Lessen governmental regulations. Ten years later (1997) the same author emphasised that another way of improving productivity and the positive impact of such an effort was to look at the construction supervisor. It was suggested that one third of construction productivity problems could be traced to poor management or lack of management. The Construction Industry Board Working Group found that although there is no simple solution to improving construction productivity, there is significant scope for eliminating unnecessary costs from the construction process. Many of these measures have already been successfully tried and tested by key pathfinding companies. They include risk management, 12 value engineering, life-cycle costing, prefabrication and standardization (Construction Industry Board, 1996). 2.4 Monitoring and Reporting A recurring theme throughout the literature is that the daily report may be the most important part of project documentation. In addition to being a historical record of the entire project, the report is also a field control tool as well as a financial and budgeting tool. Pogorilich (1992) emphasises that the returns in terms of saved time and acquired information can easily justify the reporting effort. Currently, to perform project monitoring and reporting on work progress, human resources must be employed. Benefits for the computerized approach for collecting and processing site information include development of a coherent picture of the current status of a project and how it got there; faster response time in dealing with problems; integration of the site reporting, project planning, and project scheduling functions; an increased likelihood of schedule updating and speedier updating (thus leading to increased schedule credibility); help in dealing with claims; and documentation of experience in a form useful for future projects (Russell, 1993). With time, bar coding (Coble, 1995; Stukhart, 1992) and video (Paulson, Chan, and Koo, 1987; Eldin, and Egger, 1990; Williams, 1994; Noor, 1998; Kannan, 1999) will be used more extensively to supplement human sensors, but only for specialized or narrowly focused measurement tasks. To date, several emerging computer technologies can be applied to construction. These include hypertext and hypermedia (Williams, 1994, 1997), portable pen-based computers (McCullouch and Gunn, 1993) and wireless communications (Boussabaine, Grew and Currin, 1999). Hypermedia systems can link text, pictures, videos, and sounds. 13 Results from two field demonstrations indicate that the pen-based portable computer possesses the potential and capability to automate construction field-data collection (McCullouch and Gunn, 1993). Related work is that of Elzarka, Bell and Floyd (1997) in which the Automated Bridge Inspection System (ABIS) is described. This system consists of several modules that permit field bridge inspection data to be captured on pen-based notebook computers. An interesting approach to field data collection was given by Liu (1995). The Digital Hard Hat, a data communication device for communicating/capturing construction site conditions was developed. The device provides an efficient tool for real-time 2-way communications. There has been no evidence that the construction industry has taken advantage of this device to date. MULTROL, a multimedia project control and documentation system, was developed by Liu et al. (1994). The retrieval of project information is assisted by a graphical user interface and user-definable queries to support various needs of construction management. This system allows the storage and retrieval of project information in the format of text, image, video, and sound. Another software package described in the literature and used for keeping track of field data among its other features is called WorkPlan (Choo, 1998). It is a database program which guides the user step-by-step through the process of defining work packages, identifying constraints, checking constraint satisfaction, releasing work packages, allocating resources, and then, at the end of each the week, collecting field progress data and reasons for plan failure. At present, site reporting for the majority of projects is less than satisfactory. As a result, the ability to develop a comprehensive understanding of how various site events affect productivity is severely limited. 14 2.5 Analysis of the Construction Productivity Literature Special emphasis was given to collecting relevant papers dealing with construction productivity and data collection that have been written over the last 25 years. Approximately two hundred papers were collected. Only 50 of these were chosen to fit in the following table because the majority of them either did not treat actual data or addressed possible predictive relationships for productivity as a function of one or more factors. The main objective of such a thorough literature research was to give some insights as to what is the state-of-the-art in terms of knowledge about factors that influence productivity, how these factors can be recognized and measured, and how these factors can be influenced by certain management actions in order to contribute to higher productivity and/or assist in avoiding construction claims. Ideally, it would be nice to develop a set of productivity relationships, which are unique and can be used on any construction project. However, actual relationships are much more complicated and very rarely can be expressed through one or more explicit formulas. Further, the creation of accurate mathematical models require accurate and abundant construction data obtained from the field. The lack of such data poses a large stumbling block (see Chapter 3.2.3 Lessons Learned in Monitoring and Obtaining Accurate Data). Mitigating against accurate data collection for the purpose of developing relationships is the observation that it is a time consuming, full-time job that requires that the person(s) who collects the data has construction knowledge pertaining to methods, site organization, governing regulations, and so forth. The papers were found mainly in the following journals: ASCE Journal of Construction Engineering and Management; Canadian Journal of Civil Engineering; Computing in Civil Engineering; ASCE Journal of Computing in Civil Engineering; AACE Cost Engineering; and AACE Transactions. The distribution of articles used as to source is shown in Figure 2.6.1. 15 0 ASCE Journal of Construction Engineering and Management • AACE Cost Engineering 4%2%2%2% • AACE Transactions 14% 66% E3 ASCE Journal of Computing in Civil Engineering GO Canadian Journal of Civil Engineering • Computing in Civil Engineering - Proceedings El National Research Council Canada Figure 2.6.1 Source of Articles Included in the Literature Research The following headings were found to be useful for the appraisal of the construction productivity literature: 1. Type of the collected data - to show what types of projects were included and what type of construction activities were monitored for the purpose of conducting productivity analysis studies; 2. Productivity issues - to show what productivity factors (e.g. weather, accessibility, change orders, etc.) were chosen and monitored to try to explain relationships between them and productivity; 16 3. Monitoring method - to show what type of monitoring method was used in research (e.g. work sampling, video camera, stop watch recording, etc); 4. Transferability - to describe if the results of the research can be used and transferred to other projects; 5. Qualitative vs. quantitative analysis - to show if the research was conducted using qualitative or quantitative parameters, and/or if the results of the study can be quantified or not; 6. Predictive relationships -to show if none, one, or more mathematical relationships were derived for predicting productivity as a function of one or more factors; 7. Threshold - to describe the starting point of an experience for discovering either new knowledge or extending the existing knowledge pertinent to construction productivity. The analysis of the literature in accordance with the above headings is presented in Table 2.6.1. 17 THRESHOLD PREDICTIVE RELATIONSHIP QUALITATIVE vs. QUANTITATIVE ANALYSIS ' 3 TRANSFER-ABILITY MONITORING METHOD PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc.) TYPE OF DATA C O L L E C T E D PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION THRESHOLD l PREDICTIVE RELATIONSHD? H QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only TRANSFER-ABILITY o Z MONITORING METHOD Two work sampling types: tour approach and alternate method applied on a specific crew PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Comparison of eight work sampling methods illustrating some of the more common pitfalls of work sampling studies TYPE OF DATA C O L L E C T E D Data from 8 work sampling programs. Conducted on seven power plant projects and on one large industrial project 5 were applied on new projects, 1 on the overhaul of fossil power plant, 1 on refuelling outage at nuclear power plant At least one program was applied to both maintenance and new construction PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Work Sampling Programs: Comparative Analysis, H. Randolph Thomas, Jr. and Mason P. Holland, 1980 THRESHOLD Introduced a new decision-making methodology, crisis decision analysis, as an appropriate tool for aiding the project manager in making critical decisions in a rational and time-responsive manner PREDICTIVE RELATIONSHIP QUALITATIVE vs. QUANTITATIVE ANALYSIS Both qualitative and quantitative TRANSFER-ABILITY Yes MONITORING METHOD No monitoring -hypothetical example of sewage tunnel project PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Crisis decision analysis, for aiding the project manager in strategic judgements caused by failures, poor performance or low productivity during construction TYPE OF DATA C O L L E C T E D Data for three alternatives of a hypothetical sewage tunnel project: breastboards, grouting, and well-point (quantity of water inflow, degree of settlement, permeability of soil, degree of contamination, rate of productivity) PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Critical Decision Making During Construction, David Ashley, Kazuyoshi Uehara, and Burke E. Robinson, 1983 THRESHOLD Benefits from the "On Site Performance Programs" implementation: site management improvement, increased safety level, reduced manpower turnover and higher working norms Further investigation of weather impacts on productivity for different construction projects PREDICTIVE RELATIONSHIP No relationship Two non-linear equations were determined, one for cold or cool weather1 and another for hot or warm weather2 QUALITATIVE vs. QUANTITATIVE ANALYSIS Both quantitative and qualitative Quantitative only -temperature and humidity vs. productivity TRANSFER-ABILITY Yes, to similar projects Yes, to similar projects MONITORING METHOD Study of records and documents; interviews; questionnaires; work sampling; observations and quality circles Historical data from a number of different projects used PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc.) Impact of management, safety level and manpower turnover on productivity Impacts of temperature and humidity on overall construction productivity TYPE OF DATA C O L L E C T E D One-month productivity data for 150 apartments, approximately 800 sq ft each in rows of houses 4 stories high Data from a number of different projects for activities: manual and excavation with equipment, erection, masonry, electrical work, and carpentry PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION On Site Performance Improvement Programs A.Laufer, 1985 Climatic Effects on Construction Enno Koehn, and Gerald Brown, 1985 s o U t/i u <u o. ce PH T3 et 3 > U 3 o u PH e o *-« o 3 u © o >> e < r i « I e <§ 1 •8 S 1 II II i oi p< oi VO VO O O THRESHOLD 1 PREDICTIVE RELATIONSHD? Developed work modules which address quantity development, resource definition, and production and cost analysis QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only (in general terms) TRANSFER-ABILITY Yes, to road construction projects MONITORING METHOD PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Productivity analysis module operated on data shipped to it from the resource definition module TYPE OF DATA C O L L E C T E D None PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Productivity Analysis of Construction Operations, Amir Tavakoli, 1985 THRESHOLD Hypothesis that the unit rate productivity projection model has high accuracy was strongly supported by given statistical results PREDICTIVE RELATIONSHIP Work sampling information showed a close relationship to labour productivity data QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only TRANSFER-ABILITY Yes MONITORING METHOD Two forms of questionnaires for the work sampling data and for labour productivity data PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Relationship between work sampling and unit rate productivity TYPE OF DATA C O L L E C T E D 45 work sampling data points from 11 nuclear power projects and 4 fossil fuel power projects PAPER, AUTHOR(S), AND YEAR OF PUBLICATION Work Sampling can Predict Unit Rate Productivity Fwu-Shiun Liou and John D. Borcherding, 1985 THRESHOLD PREDICTIVE RELATIONSHIP QUALITATIVE vs. QUANTITATIVE ANALYSIS TRANSFER-ABILITY "1 8 S3 6 d _ ctJ W rt •d a i/i ^ £2 g P TJ o A •» 0 . 0 o e o U b V D. « PM T3 w •(-< « 2 3 MONITORING METHOD PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) TYPE OF DATA C O L L E C T E D PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION § ^ .S3 2 d § ^ d S ' | S3-2, •O o PH C o •*•> w s s . -(-> (A s © U Vi >? s < so If £ &3 THRESHOLD PREDICTIVE RELATIONSHD? QUALITATIVE vs. QUANTITATIVE ANALYSIS Both quantitative and qualitative TRANSFER-ABILITY Yes, only in generic way to construction outage projects MONITORING METHOD 4 construction home-office managers, 3 constructors and 4 owner field managers and 80 nonmanual field personnel interviewed PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Adverse effect of outage work upon the efficiency of nonmanual4 personnel. Problem areas included orientation and training, paperwork, work schedule, containment work, and shift turnovers TYPE OF DATA C O L L E C T E D Case study: maintenance and outage work which took place during the early 1980s at a nuclear power plant. Data included working conditions, work schedules and other problems during the course of work as well as specific departmental problems PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Factors Affecting Outage Construction Efficiency, JackH. Willenbrock, H. Randolph Thomas, and Paul J. Francis 1987 THRESHOLD Established framework for quantifying the effects of various factors on construction productivity PREDICTIVE RELATIONSHIP Predicted daily performance ratio in relation to air temperature and relative humidity5 QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only TRANSFER-ABILITY Yes MONITORING METHOD Standardized daily data collection -observations PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Effects of temperature and relative humidity on productivity TYPE OF DATA C O L L E C T E D Data from three commercial projects re structural steel, masonry, and formwork. Daily data for 78 work days included the crew size, absenteeism, man-hours, and production PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Factor Model of Construction Productivity H. Randolph Thomas, 1988 THRESHOLD l 1 PREDICTIVE RELATIONSHD? Reviewed the formal techniques that have analytical nature and demonstrated how to apply them. Techniques reviewed included: crew balance chart, flow diagram, process chart, and construction operation simulation l QUALITATIVE vs. QUANTITATIVE ANALYSIS Both quantitative and qualitative Quantitative only - active and inactive worker counts TRANSFER-ABILITY Yes to the construction tasks that are repetitive Yes MONITORING METHOD The times assigned to the activities were taken from the average cycle as determined form the time lapse film of the actual crew Physical recording conducted by one person who recorded active and inactive behaviour PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Described techniques for construction productivity improvement for completion of repetitive tasks Applying activity surveys as a supplemental productivity measurement tool which measured level of activity of the workforce TYPE OF DATA C O L L E C T E D Data from concrete placing and finishing a service road which was obtained from a group of students' study in the author's productivity improvement class Data from two petrochemical projects constructed in the U.S. Gulf Coast region PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Analytical Techniques to Improve Construction Productivity Dr. Luh-Maan Chang, 1988 Activity Survey Impact on Construction Productivity Stephen G. Goranson, 1988 THRESHOLD PREDICTIVE RELATIONSHIP <2 CA 3 o •U '5. -rt T3 'Si If IIS o J u P .2 o & % s a £ I &,.§ QUALITATIVE vs. QUANTITATIVE ANALYSIS cu T3 cn 3 § GO o ™ CD -t! § -5 1 3 re O W TRANSFER-ABILITY MONITORING METHOD cn § tl -2 ^ e i 1««g 3 a .3 -3 54 -rt w Q u u u u n ifl PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) - J3 B ° •s g M S .2 o O re T3 « J re o 6 a 8 ? « - "2 C CO 1) re o to CA b o ? U U TYPE OF DATA C O L L E C T E D O CD s £ -a a 8 a g o y s PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Sill1-, I I I •a t3 THRESHOLD 1 CYCLONE-based simulation: nonsteady-state processes in construction, allowed input of the randomness of construction operations into models PREDICTIVE RELATIONSHIP Model: implementation of co-ordination skills, muscular power, and intellect to convert materials, man-hours, and energy, by use of information, tools, space and equipment, into units of output QUALITATIVE vs. QUANTITATIVE ANALYSIS Both quantitative and qualitative Quantitative only TRANSFER-ABILITY Yes, for analysing site management and control systems when given a particular company's data Yes, in general terms -(advisory) MONITORING METHOD Interviews with craftsmen, foreman, general foreman, supervision, and management PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) A conceptual model of the construction process, defining goals for management and control systems to support the craftsman's needs in the field is presented Effects of storage limitations of flow units and breakdown delays in combination with different storage conditions on productivity TYPE OF DATA C O L L E C T E D Data from interviews with craftsmen, foreman, general foreman, supervision, and management for 11 projects ranging in size from $45 to $100 million Two hypothetical scenarios (concrete truck waiting line and defective vibrators) to demonstrate the effect of limited queue capacities and equipment breakdowns PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Conceptual Construction Process Model, Victor E. Sanvido 1988 Simulation of Nonsteady Construction Processes, Leonhard E. Bernold, 1989 THRESHOLD Research indicated that formal material management programs have the potential to yield significant construction cost savings PREDICTIVE RELATIONSHIP Analysis provided order-of-magnitude assessment that is useful in evaluating effect on other projects (quantitative estimate of work-hour losses from ineffective material management) QUALITATIVE vs. QUANTITATIVE ANALYSIS Qualitative -presence of adverse material-related conditions. Quantitative estimate of work-hour losses from ineffective material management practices TRANSFER-ABILITY Yes MONITORING METHOD An independent observer visited each case study project daily. Used method "rules of credit" methodology PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) The adverse impacts of ineffective material management practices on productivity TYPE OF DATA C O L L E C T E D Data from two structural steel erection projects. An independent observer collected data according to 25 productivity factors (material management; work content and constructibility issues; construction methods; environmental conditions etc.) PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Impact of Material Management on Productivity -a Case Study, H. Randolph Thomas, and Victor E. Sanvido, 1989 THRESHOLD Future use of camcorders: benefits such as improving communication between management and labour, providing records of activities for training, safety, evaluation, and legal disputes PREDICTIVE RELATIONSHIP • QUALITATIVE vs. QUANTITATIVE ANALYSIS Both quantitative and qualitative TRANSFER-ABILITY MONITORING METHOD 8-mm video camcorder, a 1/2 in. VHS camcorder, an editing controller, and a cassette deck PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Impacts of better communication, more effective use of management time and improvement of constructibility, methods for erection and effective use of labour and equipment on productivity TYPE OF DATA C O L L E C T E D Data collected for precast units, tilt-up panels and preengineered metal buildings during the construction of a major state prison PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Productivity Improvement Tool: Camcorder Neil N. Eldin and Stephen Egger, 1990 THRESHOLD Combination of two models could yield the first comprehensive model of crew-level, labour-intensive construction operations PREDICTIVE RELATIONSHD? Predictive relationship between units of work and workhours per unit of work for different factors affecting productivity6 QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative: both models are based on factors that exist in a form that can be statistically validated TRANSFER-ABILITY Yes MONITORING METHOD Video, photography, stopwatch timing, and work sampling PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Factor model -project, site, and management factors affecting productivity, and expectancy model of motivation - why a crew exerts an effort to perform and how this effort relates to productivity TYPE OF DATA C O L L E C T E D Data from various work-study models borrowed from industrial engineering. For factor model the database included 11 commercial projects and 570 days of masonry activity data. PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Modeling Construction Labor Productivity H. Randolph Thomas, William F. Maloney, Ann Aibor, R. Malcolm W. Horner, Gary R. Smith, Vir K. Handa, and Steve R. Sanders, 1990 e o U IT C U a. CCS PH T3 C U et • mm _> '& w S "O o u PM e o *-* u s u •<-> VI e o U C M O Vi Vi "3 B < IS cs H .8 " "0 OH P .2 tN cn THRESHOLD Data collection forms by Thomas and Sanders (1988) are suitable for research purposes but should be modified and simplified to meet the requirements of specific projects and so that data can be more easily gathered by field personnel PREDICTIVE RELATIONSHIP Productivity measurement procedures manual by Thomas and Sanders (1988) was proven adequate in providing forms for data collection needed for measiuing productivity QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative (crew size, temperature, absenteeism, length of the work day) and quahtative (weather conditions, interferences congestion, rework, etc) TRANSFER-ABILITY MONITORING METHOD Physical measurements, visual observations, reviews of time sheets or payroll records, and discussions with crew supervisors PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) A case study based on the application of information in CII Source Document No. 35 and Thomas and Sanders' manual for collection productivity and related data TYPE OF DATA C O L L E C T E D Masonry operation data for two on-going construction projects (a library and a university administration building) PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Measuring Construction Productivity Luh-Maan Chang, October 1991 e © U Vi tm C U Q. « PH T3 C U •*•> u s •o o u PH e %3 u s u so e o U C M O cn • MM in e < s« c i ja « THRESHOLD PREDICTIVE RELATIONSHIP QUALITATIVE vs. QUANTITATIVE ANALYSIS TRANSFER-ABILITY 60 a t; 60 ,<D Pi y O -D "I CD "0 "9 2 is •a o u I ! I , •g p i ° £ c° B ^ © 1 u is -° I d IH O ll> C w- 5 «j o a 2 ?" > o <D 4 ) u MONITORING METHOD PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) <S &a 2 )= £ 6 I a § 73 TO TYPE OF DATA C O L L E C T E D PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION 60 § « .5 1'S f a l l 111 a « p vi s p w C IH n C t-a. p a, y tl -p & a 1 § * ! M i p TO Ov .3 cn HH 13 y « 1 3 o x cn jn © P _CD y 7 3 * ! •3 8 p ° e v? d P © "fi "* 1 s •a 0) T 3 TO g B 'I d CD P i d P CU d ^ K 5.2 i3 o P a o .3 p,Q p, to p, 3 J3 8 g O PH I W> « i-H o o .a is P c o U la C U a CCS PH 73 CU "cu _> u s © PH W5 e o U C M O >> n a < l-H Wo a H in THRESHOLD Work-sampling studies cannot be used to predict labour productivity or quantify inefficient work hours PREDICTIVE RELATIONSHIP Published articles about hypothesis that direct-work percentages from work-sampling studies can be used to predict labour productivity were misleading QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only TRANSFER-ABILITY o Z MONITORING METHOD Work sampling PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc.) Using linear regression models, tried to determine if direct work is related to productivity TYPE OF DATA C O L L E C T E D Two data sets: 158 work-sampling studies from 30 nuclear-power-plant construction projects and direct work percentages for specific crafts on three nuclear projects PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Labour Productivity and Work Sampling: the Bottom Line Randolph Thomas, 1992 THRESHOLD i PREDICTIVE RELATIONSHIP No predictive relationship was found QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only TRANSFER-ABILITY o MONITORING METHOD Data gained from different construction literature PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc.) Reviewed the construction literature on the effects on labour productivity of scheduled overtime TYPE OF DATA COLLECTED Three groups: studies based on project records, studies in which sources of data are unknown, and studies done in the manufacturing sector PAPER, AUTHOR(S), AND YEAR OF PUBLICATION Effects of Scheduled Overtime on Labour productivity, H. Randolph Thomas, 1992 THRESHOLD The first reported effort to collect productivity in a standardised manner from multiple projects on the international level PREDICTIVE RELATIONSHIP Shown: the more disruptions, the worse productivity. Further, the average degree of productivity improvement can be achieved through better management control QUALITATIVE vs. QUANTITATIVE ANALYSIS Both quantitative and qualitative TRANSFER-ABILITY crt CU >> MONITORING METHOD Data collected daily using a comprehensive procedures manual (Thomas et al. 1989) PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc.) Disruption impacts on productivity, management factors affecting labour productivity, and an examination of the extent of control a contractor has over labour productivity. Validation of factor model TYPE OF DATA C O L L E C T E D Case study projects: data (manpower, quantity measurement, design features, weather, construction methods, project organisation and features, management practices) collected from 13 masonry . projects from seven countries PAPER, AUTHOR(S), AND YEAR OF PUBLICATION Comparison of Labour Productivity, H. Randolph Thomas, Steve R. Sanders, and Suha Bilal, 1992-a © ? v o. eg PH "9 ii •«-> CS I u 9 T 3 O u. PH a o • M • * s (fi a o U o .SS "on >> "« S < r i cu MM H THRESHOLD PREDICTIVE RELATIONSHIP t3 ca cu c p 5 S " « K ! J 8 8'SI IS cu J3 73 cn 2 cu o '3 g | "8 n i l i t s u h <U fe 2 4) -fi O 6 | s 1) 3 > cu a i -cn 8 U O CO * 3 « S- • ^ ca v cu .^L ' r j +"1 *T3 J s S & g-v JS 9 S « cn cu CU T3 x s "S ' '55 tj £ ^ 2 i c*j o c cu O -a '3 •<-» ca cu «C > -1 -cu * i o. « s x ca cs •8 .2 2 +-• ts ? -° o opS —> <u 5 2 -S _e i-, o *-* cu S ~ H •S cu O QUALITATIVE vs. QUANTITATIVE ANALYSIS TRANSFER-ABILITY MONITORING METHOD a o •s -a.1? a I § .tt 2 ^ 3 T 3 3 a g ta -o c ao .2 © ri -P .tt cS cr .5 8->< a, PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc.) TYPE OF DATA C O L L E C T E D 73 o O. cu Tj S v- « p Q c2 •£ &. cu c .2 «, ts-s 2 l o k.i 3 t. -S O « — 2P 2 £ o ^? ?a = PAPER, AUTHOR(S), AND YEAR OF PUBLICATION CN +J cS 3 O cu ea > a — _ tt ca Op ta ro .2 "£ M IS ta 9 'S JS 111 co o .5 £ <u w- 4-» t i . S _ J G a .s- c -a fe c o. S 3 o a. 4 h ^ bo > . , _ « • 3 -S 'ft Q & •§ « M -a « I 'I'S H y ~ ff a o U s-cu a. PH •8 s -o o u PH c o o s u •<-» t» B O U o *S a < _CU 03 H T3 X 00 tN O o + in 5 oo CN 00 II >> s :g c3 3 o T3 CU ta 3 s c2 2 1.2 a is fe 3 3 « c r II o +•• 'ti 11 cr cu cu c <u S cu • § a 3 ! 'cn \0 « ^ 4) O SX 4. O + Tu JN 4) CN •« ^ S I S tN l l S -S oo m THRESHOLD PREDICTIVE RELATIONSHD? cu a, ?P >> <L> ea 3 Ii o 1 3 « M o H300 QUALITATIVE vs. QUANTITATIVE ANALYSIS TRANSFER-ABILITY I ' l l - i l l ?•< o -2 0 DH<« MONITORING METHOD PRODUCTIVITY ISSUES CWeather, Accessibility, Change Orders, etc.) TYPE OF DATA C O L L E C T E D PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION "3 • o O CO £ 3-3 " I .2 * •a tu 2 s & 0 T3 o -3 0 CS ,ea as.* • d . o a P 2 0 0 2 -s o Q <* 53 8! 3 .2 ^1 ea R > Si J ••s-a 1 § ^ 1 1 ^ <J 00 IH 60 tN o a\ 8 C3 u Vi U CU a. PH T3 CU 3 TS O PH e u 3 U C o U Vi e -< l-H VO c4 3 CS H CO THRESHOLD Good support for site-level construction information system (it was not validated) PREDICTIVE RELATIONSHD? Proposed site-level construction information system which defined information requirements to support decision-making needs of site-level personnel constructing a facility QUALITATIVE vs. QUANTITATIVE ANALYSIS Both qualitative and quantitative TRANSFER-ABILITY Yes MONITORING METHOD Not known PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Case study: 6x600-MW coal-fired power plant. Information management data for concrete supply and transport, surveying, excavation, equipment carpenter shop, bulk stores, and material-receiving yard TYPE OF DATA C O L L E C T E D Information requirements to support decision-making needs of site-level personnel constructing a facility to improve productivity PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Site-Level Construction Information System, Victor E. Sanvido, and Boyd C. Paulson, 1992 THRESHOLD To date the factor model has been the most accurate model for forecasting labour productivity Demonstrated the potential for applying neural networks to construction operation-productivity estimates. Recommended further validation using real-job data for other types of operations PREDICTIVE RELATIONSHD? The factor-model forecasts were within 65% when only 5% of the work was completed Developed a neural-network model for estimating excavation productivity QUALITATIVE vs. QUANTITATIVE ANALYSIS Both quantitative and qualitative Quantitative only TRANSFER-ABILITY Yes Yes, for excavation productivity estimation MONITORING METHOD One person monitored each project for more than 25 site productivity factors Observation methods: stopwatch, video, and time-lapse photography recording PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Creation of a model for forecasting labour productivity Influence of environment on excavation productivity9 TYPE OF DATA C O L L E C T E D Data for 22 masonry projects as part of ongoing study of construction productivity Data obtained from an experiment with a desktop excavator model generating sample cycle-time data for training the first neural network PAPER, Lo -§,-3 AUTHOR(S),AND | | | 1 | « i £ Y E A R OF § f c ! ^ 3 ~ J i ! | U PUBLICATION | | l i | 5 | | I S Estimating construction productivity: Neural-network-based approach, Li C. Chao and Miroslaw J. Skibniewski 1994 THRESHOLD PREDICTIVE RELATIONSHIP Application of learning curve and progress curve theory to construction productivity QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only TRANSFER-ABILITY Yes MONITORING METHOD Data from the author's personal records of progress tracking. Monitoring method not known PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Suggested first approximation profiles for both typical resource loading and progress curves which plotted percent of total time against cumulative labour consumed . Use of learning curves for tracking progress11 TYPE OF DATA C O L L E C T E D Data from several projects presented: electrical systems installation in new building construction, placing of formed structural concrete, pipe pile driving, etc PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION A Pragmatic Approach To Using Resource Loading, Production, And Learning Curves On Construction Projects R.Max Wideman, 1994 e o U m u CU a « PH T3 CU C J S •a o u PH C o • u 3 u • * J cn a o U C M © SO . H I CA j £ > "eS C < vo ci CU 3 CQ H o OH 3 CO 1 a O cu tN THRESHOLD PREDICTIVE RELATIONSHIP QUALITATIVE vs. QUANTITATIVE ANALYSIS TRANSFER-ABILITY MONITORING METHOD PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) TYPE OF DATA C O L L E C T E D PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION i'1 » o. bo "3 -e § a ci tu o cu 3 tu S6 ^ 5 o E a o .<G tj -5 8, \S 3 55 5 tu o o _ 3 '5 .9 tu e U cu o. CS PH T3 CU <-> CS %-» u s •o o u PH B o B O U c*_ o cn _>> "es B < i—I VO rs* 23 CS H K cHl w 1*0 |-< b " S 2 S a 7 THRESHOLD An idea of the use of an expert system to predict the construction production rates as a recommendation for future work Found out that when the ripple effect was present, the workhours required to perform the work increased by an average order of magnitude of almost three PREDICTIVE RELATIONSHIP No relationship Regression model showed that one disruption per week results in a 9 percent loss of performance. Given a nonlinear regression model12. Regression equation can be used to estimate the loss of efficiency caused by disruptions QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only Both quantitative and qualitative TRANSFER-ABILITY o Z Yes MONITORING METHOD Video recording, questionnaires and stopwatch studies Daily data collection through eight types of forms PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Effects of delays on construction productivity Quantifying the effect of disruptions on labour productivity -the ripple effect TYPE OF DATA C O L L E C T E D Data from seven construction sites with 32 concrete-placement operations were recorded Data for 19 projects included masonry, concrete formwork, and structural steel erection; electrical conduit and cable installation; fabrication of precast concrete segments for a segmental bridge; and caisson drilling PAPER, AUTHOR(S), AND YEAR OF PUBLICATION Effects of Delay Times on Production Rates in Construction John Christian, and Daniel Hachey, 1995 Labour Productivity, Disruptions, and the Ripple Effect, H. Randolph Thomas and Amr A. Oloufa, 1995 Tf THRESHOLD Study limited to the transients caused by the start-up development. It could be also conducted to evaluate the transient effects from operational delays: equipment breakdowns, management and personnel delays PREDICTIVE RELATIONSHD? Productivity measurements applying different stopping rules14 deviated up to 17%. Start-up effects had greater impact on those operations with longer durations QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only (duration of different work tasks included in material-hoist and asphalt paving operations) TRANSFER-ABILITY Yes, just for material-hoist and asphalt-paving operations MONITORING METHOD Unknown - data obtained from previous case studies PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Effects of productivity transient caused by the mobilization process (start-up development) of construction operations every day TYPE OF DATA C O L L E C T E D Two construction operations, a material-hoist and an asphalt-paving operation were taken from the MicroCYCLONE Systems Manual (Halpin, 1990) as case studies for productivity transients investigation13 PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Graphical-Based Method for Transient Evaluation of Construction Operations Rong-Yau Huang and Daniel W. Halpin, 1995 O CD <D M 8.1 tt a> CD CU THRESHOLD PREDICTIVE RELATIONSHD? QUALITATIVE vs. QUANTITATIVE ANALYSIS _ o a -a -a " s a t * tS C O IH a <D 1113 1 S T3 T3 <u h i. 5 o o ftS S 2 a a » a 2 o. a, a CJ .a a o, a <u a -2 -5 S tH g CM OH 1 •a s i TRANSFER-ABILITY MONITORING METHOD PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) TYPE OF DATA C O L L E C T E D PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION « 3 i L p -2 -a >« 2 .3 I 3 1 1 1 1 ^ a, -I <>; £ oi u a « 5 •a a O H * * 15 •a O i + _ cn W | H i i3 " O te> 3 •as -a a & « s , 0 \o a 2 na S «« & | CA a D <2 OH £ * 3 <L> 2 U C k e vo •2 -i? 53 & . ov tS •£ § E "3 W 2 2 " g S £ -g 1^1 Hi I -§ ? § S ^ S S3 3 o C c g" e o U u CU a « PH •O CU PH S •a o e s o o cj 3 QJ CJ O 1 c#) IH o o a CJ a cu - H i t 8 " oo 1 * -a" ^ •<§ 8 t« * "S On-a o o o a <-> . § •§ <a «g -8 cu o I ca <2 0>2 -a 3 R <« 2 1 1 o OH OH a 3 •§ | 2 a 3 S -S II E J < -2 ^ ^ 3 2 3S O cn .a 3 O H I VO THRESHOLD Requirement for extensive data collection. Investigation benefits: development and implementation of a practical artificial intelligence tool PREDICTIVE RELATIONSHIP Created a neural network model for construction productivity estimates QUALITATIVE vs. QUANTITATIVE ANALYSIS Both used. Quantitative data were described by numerical values. Qualitative data-described mainly ratings and descriptions TRANSFER-ABILITY Yes MONITORING METHOD Data sheets (four types of questionnaires) were used to collect relevant data for concrete formwork PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Labour productivity in m-hour/unit TYPE OF DATA C O L L E C T E D Detailed data collected for the construction of formwork for foundation walls for utility building PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Neural Network Model for Estimating Construction Productivity Jason Portas, and Simaan AbouRizk, 1997 THRESHOLD PREDICTIVE RELATIONSHIP QUALITATIVE vs. QUANTITATIVE ANALYSIS TRANSFER-ABILITY •a s O I Si i .8 «> i-c H O1 MONITORING METHOD 8 TJ "I b a tS 2 =3 a 2 J2 rt T3 5= ?i § 2 t/) o -S a 6 oo PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) TYPE OF DATA C O L L E C T E D •a § O 'o ° - p rt D Q "3 y 5° FT OH 2 s <J o a 31 PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION I ta s c— tt; o j ^ tc P r3 « £ 2 ' S i THRESHOLD PREDICTIVE RELATIONSHIP QUALITATIVE vs. QUANTITATIVE ANALYSIS TRANSFER-ABILITY MONITORING METHOD PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) TYPE OF DATA C O L L E C T E D PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION o O CJ T 3 t i •B 6 I I ) O ft oo o CJ a it** 5 OH T J * -3 6 -a 1 3 I ssa r t § * I p k ; 2 M U > U 2 .g S ' g ! S a a I £ -3 ^ p t/3 If a 2 I i i i P W O „ • CJ o o „. *i 00 P H *J CJ 8* S 1 ! LH CJ CO S H O y O ti i2 .5 cj co cs OH 3 ss K -3 if a l § "g >- s * & a % Ci > -CJ - -V P. 2 y -a _ ~ >- o I o o 3 o w § . 2 a S s o 1 II o a <-? o S U -8" is & PH § •o * « "o 15 a | •fi +» P 3 OH T3 o * n g ^ T J «"2 ^ S © OH U eg a t_ CJ .2 | -3 £ I T t — T J CJ §1,1 II H H ^. a- 8 « g " • h oo E2 2i • >w fe^ . o CN a fe I bo <u •a & <N g CN * -II ] § 2 'ji ON THRESHOLD First step toward the change orders quantification. The equation 19can be used to determine the amount of lost efficiency from change orders, but is just one measure and is not the end for future negotiations hours PREDICTIVE RELATIONSHD? The model described was a good predictor of "delta" -*the difference between the base project labour hours (actual hours - change order hours) and the original estimated labour QUALITATIVE vs. QUANTITATIVE ANALYSIS Both qualitative and quantitative TRANSFER-ABILITY Vi OJ MONITORING METHOD Questionnaires asked contractors to indicate if the job being considered was f*f*_ • I. t. i _ i affected by change orders PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Effect of change orders on electrical construction labour efficiency TYPE OF DATA C O L L E C T E D Data from forty-four projects from five electrical contractors were collected. Project types ranged from power plants to institutional and commercial buildings. Contractors were asked if the job was affected by change orders PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Quantifying The Effect of Change Orders on Electrical Construction Labor Efficiency, Awad S Hanna; Jeffrey S Russell; David Thomack; 1998 3 o 3 4> © -a O m THRESHOLD PREDICTIVE RELATIONSHD? "8 s I s 6 1 8 .2 Q 73 8 S II O H O •a fe gn-a eg «i 111 H i s QUALITATIVE vs. QUANTITATIVE ANALYSIS Si S •a g _te> TRANSFER-ABILITY MONITORING METHOD IH " O I g •a s !! H O v< CJ O o "a •13 -a I •« o 3 « s i PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) <L> 60 g -a CQ 0 (=i -2 I CJ IH OH •«s •§ i w 5 8 TYPE OF DATA C O L L E C T E D . . 60 IH CH . -<2 42 *o .o "3 a « te J H g 8 IH O 8 1 1 i & . *3 11 o •s S3 <u s « PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION cu §0 - O v. IS) " ON THRESHOLD Suggested method shown to be generic, systematic, scientific, clear, easy to use, inexpensive, accurate, and unbiased, unlike many other known methods PREDICTIVE RELATIONSHIP QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only TRANSFER-ABILITY CO MONITORING METHOD No monitoring. Used the existing contractor schedule and daily inspection records PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Delay analysis using Contemporaneous Period Analysis Technique TYPE OF DATA C O L L E C T E D Data gained from contractor's schedule for 100,000 ft of steel underground water pipeline construction, showing major pipeline activities; trench excavation, pipe laying and trench backfilling PAPER, AUTHOR(S), AND YEAR OF PUBLICATION Generic Methodology For Analyzing Delay Claims Saied Kartam, 1999 THRESHOLD Found out that more research was needed for the purpose of the development of reliable performance indicators that can be applied to a number of different projects PREDICTIVE RELATIONSHIP Developed the relation for the performance factor21. Also, the Management Disruption Index (Thomas and Oloufa, 1995) was used22 QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only. Differences in labour productivity are quantified using the multiple regression technique TRANSFER-ABILITY Yes, only partially because project data were limited20 MONITORING METHOD Manual procedures PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Impact of material delivery practices and adverse winter weather conditions on labour productivity for three case studies TYPE OF DATA C O L L E C T E D Data for three steel projects with three steel delivery strategies. First -steel erected directly from the truck. Second -steel off-loaded, sorted, and then erected. Third project - three bulk deliveries of steel PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Loss of Labor Productivity due to Delivery Methods and Weather H. Randolph Thomas, David R. Riley, and Victor E. Sanvido, 1999 ca 8 r" M S a &. a Q THRESHOLD Comprehension of construction complexity and construction productivity relations PREDICTIVE RELATIONSHIP TheDPandPMP correctly identified the best and worst performing projects. Both were rehable indicators of project performance QUALITATIVE vs. QUANTITATIVE ANALYSIS Both-quanutative for baseline productivity values, and niialitative for disruptions craft and management practices TRANSFER-ABILITY Yes, to masonry jobs, concrete form-work and structural steel erection MONITORING METHOD For each project, the data were collected using standardized data collection procedures PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc.) Two measures were proposed to measure the performance of individual projects: the disruption index23 and the project management index24 TYPE OF DATA C O L L E C T E D The 2 3-masonry project database was tested against an 8-project database of concrete formwork and a 12-project database of structural steel erection PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Construction Baseline Productivity: Theory and Practice H. Randolph Thomas and Ivica Zavrski 1999 THRESHOLD Introduction of CRANIUM seemed to greatly minimize the effect of disturbances on the crane operations and to improve productivity and reduce cost. Techniques described might be used as an evaluation tool for training programs PREDICTIVE RELATIONSHD? o Z QUALITATIVE vs. QUANTITATIVE ANALYSIS Only quantitative TRANSFER-ABILITY Findings -useful, but no transferability MONITORING METHOD Observations with respect to time creating the time series PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Comparison between the control (normal practice using a tagman) and the CRANIUM case which is a video system that allows a crane operator to have direct real-time visual feedback of what is happening at the lifting point even in a situation where a direct line of sight does not exist TYPE OF DATA C O L L E C T E D Data obtained from the experiments with three different levels of difficulties25 performed by Lorain 45 metric ton truck crane with 18m of boom PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Time Series Analysis for Construction Productivity Experiments, TariqS. Abdelhamid, and John G. Everett, 1999 JJ « a a o U a « PH CU 73 O U PH e %-> o s 1m •** Vi a © U CM © Vi Vi e vo tN Io CS H | U „ i n BO J S o ' ^ o 73 c e e i i s > c a> 5 <L) (H s s a " S 8 CJ 2> -a 4) ro O CC) | c § 8 S 1 « fe fe £ s?^ Q, ii b fCl o St 3 a THRESHOLD Implementation of wireless computer control in construction could lead to significant timesaving over traditional paper-based management and administration systems PREDICTIVE RELATIONSHD? The results of the survey: timesaving in the order of 40-120 project workdays per year could be possible if the system was applied QUALITATIVE vs. QUANTITATIVE ANALYSIS Both qualitative and quantitative TRANSFER-ABILITY MONITORING METHOD Questionnaires sent to fifty construction companies PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) A wireless communication system for improving management control over tasks and communication between parties involved in the project TYPE OF DATA C O L L E C T E D Data from poll sent to fifty construction companies to quantify how much time is spent on site administration processes PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Increasing On-Site Productivity Through Wireless Computer Control Increasing On-site Productivity, A. H. Boussabaine, B. R.Grew, D. Currin, 1999 THRESHOLD The results showed that investing in construction planning beyond an optimum point resulted in poor project cost performance (beyond the project budget) and is therefore not likely to be cost-effective. Further research work was required to validate the findings PREDICTIVE RELATIONSHIP The relationships between planning input (ratio of planning costs to total project costs) and the probabilities of achieving poor performance and good performance were modelled QUALITATIVE vs. QUANTITATIVE ANALYSIS Both quahtative and quantitative TRANSFER-ABILITY Possibly yes, but the model is still under development MONITORING METHOD A structured questionnaire was used to collect data for the study PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Optimal allocation of construction planning resources TYPE OF DATA C O L L E C T E D Data from 52 construction projects undertaken in Australia including: the amount of time invested in construction planning, the amount of time invested in project control, planning engineers' salaries, composition of construction planning team, and project costs PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Optimal Allocation of Construction Planning Resources, Olusegun 0. Faniran, Peter E. D. Love, and Heng Li 1999 THRESHOLD The Delta approach recognizes that any disruption to a task in a sequence will impact the remaining tasks even if the change order itself does not involve these tasks PREDICTIVE RELATIONSHIP Developed equations to quantify the loss of productivity associated with change orders for impacted projects only26 QUALITATIVE vs. QUANTITATIVE ANALYSIS Quantitative only TRANSFER-ABILITY Yes MONITORING METHOD Questionnaire with factors that effect how a change order impacts the construction project was developed with the help of the CII committee PRODUCTIVITY ISSUES (Weather, Accessibility, Change Orders, etc) Actual amount of labour efficiency lost due to change orders TYPE OF DATA C O L L E C T E D Data from sixty-five mechanical and seventy-five electrical projects were collected PAPER, AUTHOR(S), AND Y E A R OF PUBLICATION Assessment of Global Impact of Change Orders on Electrical and Mechanical Construction -A Approach, Awad S. Hanna, Pehr Peterson, Joel Dettwiler, Jeffrey S. Russell, and Murat Gunduz, 2000 c © U U CU Cm « PH -B cu •<-> JS "3 Cf "O o i» PH e CJ S Vi S © U © Vi • M Vi >> "is e < JU se H 1 o 9 OO >/"> 2.6.1 Type of the Collected Data Two analyses were conducted. The intention was to show what types of projects were included and what type of construction activities were monitored for the purpose of conducting productivity analysis studies. CD Existing study data • Residental and commi project data B Industrial project data H Hypothetical data • No data 0 Other Figure 2.6.2 Type of Data Collected re Type of Project Residential and commercial projects (40%) were cited most frequently because they involve a lot of repetitive work and hence are easier to model and analyze to develop predictive relationship. Almost one-forth of construction productivity research papers used existing study data as the basis for their contribution to analyses For the case when hypothetical data were used, it is not clear how well reality was reflected in the data. 59 H Concrete placement data H Formwork data • Masonry data 0 Steel erection data • El.&mech. Work data • Excavation data • Pipe fitting data • Other Figure 2.6.3 Type of Data re Monitored Activity The construction activities that are represented the most in the literature reviewed are formwork, concrete placement, masonry and steel erection activities. Under the "Other" activity data category are the information required to support the decision-making needs of site-level personnel to improve productivity; the amount of time invested in construction planning, the amount of time invested in project control, planning engineers' salaries, composition of construction planning team, and project costs; material management; work content and constructability issues; construction methods; environmental conditions and other management aspects, etc. 60 2.6.2 Productivity Issues • Learning curve • Labour productivity 13 Management • Weather 0 Change orders • Delays • Material delivery H Disruptions • Overtime H Storage limitations • Turneovers E Poor performance • Resource allocation El Other Figure 2.6.4 Productivity Issues The productivity issues column gives the factors that were used in the various research efforts to describe different productivity relationships. According to the above graph, management, weather and change orders are the factors cited most often that influence productivity. Cited less often are the factors of storage limitation, disruption and resource allocation factors. 61 2.6.3 Monitoring Method • Historical data • Questionnaires El Work sampling rec. S Unknown E N o monitoring Figure 2.6.5 Monitoring Method The methodology cited most often for data collection was using historical data collected by others. Direct observation of construction operations is the second most frequently cited method, and the use of questionnaires takes the third position. In some cases the monitoring method was not described (10%). Several studies conducted no monitoring but used hypothetical data (6%). 62 2.6.4 Transferability Figure 2.6.6 Transferability According to the authors of reviewed articles, a large percentage (48%) of the research findings could be implemented to any construction project. 36% of the observed papers concluded that their research was limited and could be applied only to the specific projects similar to the projects studied in the researches. 63 2.6.5 Qualitative vs. Quantitative Analysis B3 Quantitative analysis D Qualitative analysis • Both qualitative and qualitative analyses Figure 2.6.7 Qualitative vs. Quantitative Analysis The majority of the analyses conducted were of the quantitative type. Qualitative analyses were carried out where it was not possible to gauge in numerical terms how issues such as craft practices, social and economic factors, site condition, and adverse material-related conditions affected productivity. ,64 2.6.6 Predictive relationship 64% 36% S Y e s • No Figure 2.6.8 Predictive Relationship Several of the research papers examined predictive relationships. They took a form of predictors in the productivity projection model, mathematical models, prediction equation for change orders, predicted daily performance ratio in relation with air temperature and relative humidity, efficiency loss given in percentage according to change orders type and frequency for the observed project, neural network model for construction productivity estimates, and a predictive relationship between units of work and workhours per unit of work for different factors affecting productivity. 65 2.6.7 Threshold 0 The threshold column in the table was meant to describe whether or not the approaches in the papers provide us with a new basis for understanding how one or more factors affects productivity and/or how to further develop the existing knowledge of the construction productivity predictive relationships in order to derive better understanding of the construction process. About one third of the analysed papers did not present any significant improvements of existing knowledge of construction productivity prediction. One third of the papers introduced incentive for further research by presenting a new, or somewhat different approach to construction productivity issues. The remaining third established frameworks for quantifying effects of various factors on construction productivity. 2.6.8 Conclusion According to the literature review shown in this chapter, it can be concluded that there is no unique and universal relationship that can be used to predict construction productivity. From the viewpoint of subsequent chapters, and especially dealing with modifications to the daily site system, some parameters/variables are often cited in the literature as important for construction productivity analyses. Therefore, the suggestion is to put more emphasis on collection and later analysis of the following productivity factors: Weather (high and low temperature values, precipitation, humidity, wind velocity) Management (proper documentation during construction which can be added in the daily report in the form of scanned documents) 66 Change orders (types of change, duration required to finish the change, resources involved in performing the change) Delays (the cause of delay, duration of the delay, time lost) Material delivery (who, when and what delivered, problems if any) Disruptions (types of disruptions, cause of disruptions, duration) Overtime (for activity and whole project) Storage limitations (type of material needed to be storied, duration of the storage limitation, time lost if any) Turnovers (what type of activity involved turnover, problems that it might have caused) Poor performance (cause of poor performance - low skill level, frequent equipment breakdowns, adverse weather impacts, etc., time lost) 67 Chapter 3 Kerrisdale Project and Site Documentation 3.1 Case Study Background Information A case study was conducted on the Kerrisdale Station Project located in Vancouver on the south side of the 2000 block of W42nd Avenue. It is a mixed use - commercial, retail and residential facility on a site measuring approximately 123 m by 40 m. The West side of the project consists of a 5-storey concrete-construction building, housing both commercial and residential floor space, including a London Drugs Retail Store. The middle and East sides of the project are dedicated to office and retail space and have a three-story wood frame townhouse development on top of the ground floor. A three-level underground parkade lies below the West and central portion of the project while a two-level parkade is located on the eastern most side of the building. The whole complex consists of 13,610m2 of retail space, 59 dwelling units, underground parking area for 330 cars, and a floor space ratio of 2.42. The construction phase value is approximately $16 million. The project is representative of many similar projects being constructed in Vancouver. A photo of the architectural model used for marketing purposes is shown in Figure 3.1.1. The four-storey building shown in the background was developed subsequent to the main structure shown in the foreground. 68 Figure 3.1.1. Mock-up of the Kerrisdale Station Project The construction team is headed by a single firm - Intertech Construction Managers Ltd, the general contractor for the project. Each of the subcontractors lacks privity of contract with the project owner. The specialty contractors, such as the demolition, formwork, reinforcement, brickwork, dry wall, mechanical, electrical, and plumbing contractors, have direct contracts with the general contractor. The owner was both price and time driven, and a fast-track delivery mode was used. Consequently, subtrades were selected based mainly on price. Excavation started on 23 June 1999, and occupancy of the commercial component was achieved in early August 2000, as planned. The project started under a construction management arrangement, with the intent being that as soon as all design details were firmed up, the contractual arrangement was to be switched to a lump sum contract. The general contractor's site office staff consisted of a superintendent and a safety attendant. At the beginning of the construction, during the excavation and shoring phase, the superintendent duties were assigned to Ken Reeve, a carpenter with more than thirty years of experience in the construction industry. When the substructure construction began, Sten Carlson, 69 a civil engineer with 24 years of experience in construction engineering and management, took over site management. In mid-November, Mr. Carlson accepted a position in the Bahamas. Ken Reeve became the Kerrisdale Station superintendent for the second time and stayed on until completion of the project. The superintendent coordinated day-to-day construction activities at the site. He was also held accountable for assuring that the quality of workmanship complied with the requirements of the drawings and specifications. The site superintendent possessed: knowledge and experience in civil, architectural and structural systems; working knowledge of mechanical, plumbing, electrical and fire protection systems; the ability to read, interpret, and understand construction plans and specifications; knowledge of scheduling as a tool of the trade; good verbal communication skills; problem identification skills; working knowledge of local building codes; knowledge of construction techniques and methods, and an ability to lead a diverse group of people. Paul was the safety attendant with 6 years of experience in this domain. Besides assuring a safe environment for workers, visitors and city official, he carried out other site office duties like answering the phone, taking construction progress photos, and preparing some of the paperwork. During the time period in which the general contractor performed work related to backfilling and preparing the slab-on-grade, the safety attendant also performed some of the field duties such as operating the bobcat, site cleaning, and taking care of minor equipment breakdowns. Head office staff included a project manager, Harold Barisoff, a carpenter with several years of construction experience. He was accountable for maximizing the profits on the Kerrisdale Station project and maintaining good working relationships with the owner, architect, engineers and subcontractors. He was knowledgeable of construction scheduling techniques; had 70 the ability to communicate well with a wide range of personalities (owner, architect, engineers, city officials, subcontractors, accountants, estimators); and the ability to detect potential crisis situations and act appropriately. His role was to analyse project documentation, to prepare project schedules and updates, to monitor project costs with respect to budget, to visit the site on a regular basis, to provide reporting to the senior management of the firm, and to chair weekly job site meetings with consultants and subcontractors. Members of the research team were allowed to attend meetings with subcontractors where the project manager discussed schedule changes and day-to-day problems. Site meetings with the construction superintendent, project manager, subcontractor superintendents, owner and architect dealt with progress evaluation. Attendees had the opportunity to present activity progress, problems such as bottlenecks in material flow, problems with equipment, delays to and by subcontractors, the lack of information, employee complaints, safety risks and so on. These presentations provided ample information to identify which operations needed attention. The project manager was supported by an estimator and cost accounting and purchasing personnel at head office. In the second half of February 2000, a civil engineer, Marc Williams joined the site office. Since lack of communication was recognized as a reason for some of the problems encountered during construction, Marc was assigned the duty of site project coordinator and looked after all trade communications for the project. Formwork and concrete placing subcontractor superintendent Bill lies was another helpful person in providing the research team with needed information. Bill took care of how best to build the substructure, as the project superintendent set big-picture targets. He was a very practical and seasoned individual, who was able to describe in general terms what he had in mind as a construction strategy. Both site and office personnel were very helpful and co-operative with the research team. 71 3.2 Documentation of Site-Activities 3.2.1 General contractor's daily report Preparation of the Kerrisdale project daily report was assigned to the general contractor's safety attendant who viewed the task as a repetitive, insignificant and boring part of his daily duties. Intertech's daily diary data consisted of the date, weather (options: sunny or overcast) and temperature data, daily summary data (usually the description of the daily activities going on the site), and visitors at the site (see Figure 3.2.1). It was filled out at the end of the working day for the first two months during the time of excavation and shoring work. Once the construction process became more complex (approximately when the first crane was erected) the routine of keeping track of daily construction events simply stopped. When it was discovered by senior management personnel that no daily reports had been completed at the site for almost two months, the superintendent took over this duty. Besides the daily report, management relied heavily upon telephone communications and site visits by project managers to glean important information regarding project performance. 72 3.2.2 Data collection methods and techniques by UBC research team A total of six students spent two months monitoring the project and collecting data. Monitoring of the project started in the latter part of June 1999 and ended in early November 1999. On any given day, at least two students were present on the site for at least half of the workday. In order to maintain a detailed record of site activities and relevant context information, the UBC research team used a research system called REPCON5 to generate daily site report formats. Refinement of these formats and the effective graphical and tabular representation of site information constituted part of the research. The effective use of this system is predicated upon the existence of a relatively comprehensive schedule of activities. The team generated such a schedule. Daily site form is shown in Figures 3.2.2 (a), 3.2.2 (b), 3.2.2(c), and 3.2.2(d). The data collected are of two types: overall project context information; and data on ongoing work tasks as described in terms of activities (both scheduled and unscheduled), extra work orders and back charges. 74 ( z 0 u Oi u w • O K S-S-a s c£ «fi O. ffS \ m o Q D I n 0 01 a 4J to b) H ! K : Id > H •4 til Q >< < < M D Q CJ X U K CC H 0 > Cu H H * 0 IX < 0 3 0) ' a -: < H Z w os Z u Oi H S D 3 a s U 2. Tr«ff1 Contr 1 1 1 111 1 « ^ WW ^ O C ** — •5 ^ i £ I- 5 g * ! x —. o « p • f s i s | M a Z3 0) z o H H 0 D D: H VI Z - I f = 3 ! 2 §-.s 3 5 3 C «2 S S ; ",S f t o o tj o : 2 a « I £ 1 : u X CC o 3 S E E | S 3 - S S « J S io z o H H 0 U Cu 10 z co Z u Q H o u < v> z H H in < a to Figure 3.2 ,2 (a) The REPCON5 Daily Site Form - General Project Data and Activity Information ' 75 5 = 1 sis s s s g 8. S. o* ~> £ £ eu «tf s l • i "ii g-e 1 i 1 i i i i 5 A i l l ! § a • 1 -i | g i S S : g s ! s ! s II O o o o o o o ! l a K ! K 1 1 ! DATES (A • ACTUAL) I START FINSH DUR 1 I i 1 1 I I I i 1 I I I 1 CODE LOC ACTIVIIT/E»0/IC DESCRIPTION 1 PAT UWOfl DESCRIPTION 1 1 f f ! 1 g 1 I I 1 l f 1 1 • 1 1 1 1 I 1 i i - 1 I § 1 i I i i -1 i § i i f f 1 I I ! § t 1 I ' I 1 1 1 I s • I I • Figure 3.2.2 (b) The REPCON5 Daily Site Form - General Project Data and Activity Information r 76 I k i 3 S g | g 8I S s i a -s. s. to n: u • a. 0 se a o s to u o a: < x u < CO 8. i Figure 3.2.2 (c) The REPCON5 Daily Site Form - General Project Data and Activity Information ' 11 Figure 3.2.2 (d) The REPCON5 Daily Site Form - General Project Data and Activity Information / 78 The first data group provides important context or backdrop information that can be used to help explain performance at the individual task level. Data elements include the following. Site Environment (temperature (a.m./p.m.) (degrees Celsius), sky condition (clear, cloudy, rain, snow for both a.m./p.m.), precipitation (mm), wind velocity (kph), ground condition (poor, fair, or good), site access (poor, fair, or good), weather effects (none, minor, significant), storage on site (poor, fair, good) Work Force (number of supervisors, number of workers, number of traffic controllers, sufficiency, skill level (high, medium, low), turnover level (high, medium, low), overtime amount (hours) Survey Work (what location, what activities, number of crews, and comment) Inspections (on what location and comment) Visitors (who and why) Accidents (location and comment) Instructions (any comment on the instruction) Deliveries (item, quantity, unit, comment) Blasting (location, comment) Equipment (resource, item, quantity, status: delivered, active, idle, returned or no status, and comment) Miscellaneous (any comment) Where possible, quantitative measures are sought, but in several cases, subjective assessments are required (e.g. skill levels, ground conditions, etc). Having construction personnel make such assessments is not easy. 79 The second data group gives better insight into the activities, extra work orders, and back charges scheduled for a given day. Data of importance include: status of a work task (postponed, started, ongoing, idle or finished); description of the work performed that day; problem sources encountered; what project participant, if any, is responsible for the problem source; an extended description of the problem source and its consequences for the work task at hand; field quantification, if possible, of man-hours and/or time lost; and suggestion or identification of actions to deal with the problem source. These activity specific data include the following: Daily status data (for every activity: finished, idle, on-going, postponed, started, started & finished, no status; comments) Problems (problem description, estimate of time lost, action: telephone, letter/memo to, letter/memo from, back charge, extra work order, oral instruction, photo, video). Work Force (number of supervisors, number of workers, number of traffic controllers, sufficiency, skill level (high, medium, low), turnover level (high, medium, low), overtime amount (hours) Equipment (activity, resource, item, quantity, status: delivered, active, idle, returned, no status; and comments) Pay Items (activity, status: finished, idle, on-going, postponed, started, started & finished, no status) Elements of the data collection methodology used by UBC researchers consisted of the: Use of construction drawings for recording the sequence of construction; 80 Preparation of photo essays of progress and construction sequences, and the video taping of construction sequences along with their analysis to determine cycle times and resource usage rates; Recording of daily weather and site conditions and daily work force data using a daily site reporting system that was fully integrated with the research schedule; Documentation of activity progress in terms of estimated versus actual duration, quantities completed, and production rates; Recording of delays and problems encountered and assessing their impact on scheduled activities in terms of days lost and manhours lost; Carrying out of detailed productivity studies of individual activities such as excavation, shoring, forming and concrete placement and conducting time and utilization pattern studies of key resources; and, Observing field and office management strategies through discussions with management personnel and attendance at site meetings. 3.2.3 Lessons Learned in Monitoring and Obtaining Accurate Data The researchers found out that there were many ways to collect daily construction data. Two of the better ones involved asking those who were involved for needed information, and observing the process to develop factual records of how work was being done. Each had its advantages. However, even when the second, or observing approach was chosen, the first was not ignored. Asking (about construction progress, activity details, work force, planned strategy for the next phase of construction, etc.) often helped in the detection of weaknesses or led to 81 suggestions for improvements, as well as disclosed the frustrations of those responsible for carrying out tasks but who lacked the essential elements to do so. When either asking site personnel for data or observing work to get data, attention was directed at both managers and individual workers. The research team found out that the workers, if approached correctly, enjoyed and took pride in being part of the information collecting and reporting efforts of the team. Discussions and interviews were found very useful for completing the reports and helping to understand the real construction world. Views gathered at the site were sometimes different. For example, it was not unusual to talk to various parties on the project (the project manager, the superintendent, the subcontractor representatives, and the workers) and get very different stories about what was going on the project. Contact with project participants ranged from informal discussions with anyone on site, to several formal meetings with the project manager, superintendent and subcontractor representatives. It was physically impossible to observe and record all the minute details of every repetition of each construction operation. Consequently, much reliance was placed upon the use of photography to document construction progress, technical details, problems, types of materials, methods of installation, and site conditions. Selection of the subject matter for picture taking was based upon the need to show as much detail of the construction process as possible. Some 500 pictures were taken. During the first five months of construction, photos were taken every day. Thereafter, the progress was tracked based on twice-a-week visits. The following information was recorded on the back of each progress photograph: date photo was taken and identity of the subject. However, to make better use of this method, researchers learned that a precise schedule consisting of the exact time and photo location should have been prepared in advance. Otherwise, without such a schedule, taking pictures leads to a number of seemingly 82 random photos with less possibility to use them in later analysis. Also, reviewing the pictures in order to extract those which show construction progress, or to produce a simplified photo essay of the steps involved in certain activities, proved to be a very tiring task. The suggestion is made to use a digital camera instead of a conventional camera for easier and faster browsing through photos. Use was also made of a video camera by the research team. This proved to be very valuable when it was desired to examine cycle times. However, the extraction of data from videos is a very time consuming and tedious process. No matter what kind of monitoring method was used, it was learned that data for the same events was often interpreted differently by the researchers involved. The following is the list of the most common causes of errors in data collection which occurred during the monitoring period: Researchers could not cover all site areas uniformly, nor could they look into every nook and cranny on the project. All observers did not interpret identical events in an identical manner when they had to use their judgement. It was impossible to avoid subjectivism. The researchers' attitude often reflected the attitude of management personnel. If their attitude was that the workers were lazy, the observers often made less of a conscientious effort to be sure that observations were correctly recorded. The procedure of gathering data was often boring and fatiguing, which sometimes resulted in recording data incorrectly or not at all. It was normal to expect that workers reacted to the presence of the research team by working harder or looking busy. 83 Carrying out this research emphasized the difficulty of accurately monitoring a site, and highlighted the level of effort and resources involved in collecting reliable data. It helped to place into perspective the likely quality of data collected on actual projects by busy site personnel who are preoccupied with advancing the work. Further, it took time to develop trust and a comfortable relationship between the researchers and site personnel. This was critical to being able to capture the complete story surrounding the events of each working day. 84 Chapter 4 Use and Refinement of a Computer-Based Tool for Monitoring Construction Process This chapter overviews features of the part of a research system directed at compiling an as-built view of a project. Contributions to the evaluation and enhancement of the design of this system are described, along with the reasoning behind the changes. 4.1 Planning for the Case Study Project Because of a lack of a detailed construction schedule by the contractor (for example, excavation and shoring was shown by a single bar spanning some two months on the contractor's master schedule) and given the objectives of the research program, the research team undertook to develop a reasonably comprehensive schedule for the first few months of construction work. Use was made of a research system called REPCON5. This system is being developed to support six views of a construction project: the physical view (what is being built and the site context), the process view (how it is being built, when, where and by whom), the cost view (how much and from whose perspective), the quality view (levels of achievement required), the change view (what changed and why), and the as-built view (what happened and why). The physical, process and as-built views were used for the purpose of planning, updating and monitoring the Kerrisdale station project. 85 For the purpose of monitoring the project, excavation and shoring were broken out by level (P3, P2, and PI), and the west and east ends of the site, in order to develop a better sense of what work should be accomplished by a given date. In order to find out the strategy for excavation, shoring and substructure construction activities and to create an accurate construction schedule, several meetings with the project manager, the construction superintendent, and the forming and concrete placing subcontractor's superintendent were held at the site. It was observed that rules of thumb were most frequently relied upon by site personnel for planning and scheduling decisions. Tactical or short-term decision-making seemed to dominate. Little discussion seemed to take place in terms of articulating as overall strategy, and then implementing it in the form of a schedule. Thus, short term strategies were changed several times during the construction not only because management was under great pressure to meet the required completion date, but also to accommodate everyday situations and problems like lack of drawings, design changes, excessive ground water, undermanning, congestion, adverse weather, change orders, delay of material, and equipment breakdown. One of the researchers' concerns while preparing the construction schedule was if the verticals, slab on grade, and suspended slab work placement would be done in two, three, five, six, seven, or eight stages (i.e. the research team tried to get construction personnel to articulate the most probable overall strategy. In reality, the contractor's strategy evolved as work progressed, and ultimately ended work on an 8-stage strategy. Initially, the strategy was described as a two-stage, or West-East strategy. The West-East strategy, with some exceptions, was followed for excavation and shoring work). The research team stopped at the seven-stage-strategy (Figure 4.1.2), and the final UBC construction schedule for the substructure of the Kerrisdale Station Project consisted of 90 activities (It should be noted that a REPCON5 activity can consist of one or more work locations, thereby mapping onto multiple CPM activities). 86 Eventually, the forming subtrade adopted an eight-stage-strategy. Figure 4.1.1 shows the linear planning chart for construction in seven stages, updated as of 23-June-1999. Appendix 1 contains the complete research construction schedule for the scope of work studied, in the form of a logic (activity code description and type, production data, predecessors), an activity list, and early start time bar chart. Figure 4.1.1 As-Planned Schedule with Seven Stages Updated on 23-June-1999 87 1 3 5 7 2 4 6 Figure 4.1.2 The Definition of the 7-Stage Strategy. Drawing not to Scale. The construction management/general contractor company prepared a preconstruction master schedule using Microsoft Project early on during the design development process. The construction phase was described in 30 activities. This schedule was made by first setting target dates and then assigning time allowances (see Figure 4.1.3 for an excerpt from the schedule). Bfcy Jutxt July .AwyMrt f SB j^filSfij ~~" Octoto#f Nov*mt>#r c I N T E R T E C H C O N S T R U C T I O N L T D •ENTSj IKS BUDGET | 13 3 Utoyzo O N D O N OR U O S + May 73 S T O R E STOS ABATEMENT i s Et-EV J Uay tl E X C A V A T101*4 j MSCH. EL£C. HMOWY. STEEL j J » > T ^ a n a TENOER R E M A I N I N G M A J O R T R A O E * » [ J M W tf. | Jun 30 FOUNDATIONS ft PARKADEH GRADE CONSTRUCTION Nova 2ND FLOOR ft LD R. Figure 4.1.3 Excerpt from a Preconstruction Master Schedule Made by Construction Management Company 88 The general contractor's superintendent prepared a hand drawn bar chart in mid September for the construction of the substructure (see Figure 4.1.4 - note the West-East phasing). The superintendent stated that it was deliberately meant to be too aggressive and was not reflective of the views of the forming and concrete placing subcontractor's superintendent. According to this schedule, the ground floor would be finished 7 weeks after the second tower crane was erected on November 15, 1999. It was 6 weeks earlier than the forming and concrete placing subcontractor's schedule showed. The time difference between the two viewpoints was split, with both parties agreeing to the split and with both parties agreeing that the ground floor should be completed in the first week of December. Figure 4.1.5 shows the first page of the three-page schedule made by the forming and contract placing subcontractor's superintendent (the complete schedule is contained in Appendix 1). The general contractor made a pour schedule using Microsoft Project which reflects the forming and concrete placing subcontractor's schedule. With the agreement that the ground floor should be done by the first week of December 1999, many of the activities located on the West side of the site became critical. According to the UBC schedule (7 stages, updated as of 23 June 1999) the substructure was forecasted to be finished on January 15, 2000. As stated previously, the construction management company prepared no detailed construction schedule during the excavation and shoring phase, and only in the fourth month after the construction began (September, 1999) was a more detailed scheduled prepared for the superstructure construction using Microsoft Project. None of the schedules developed were resource loaded. 89 Figure 4.1.4 Hand-Drawn Schedule Made in Mid September 1999 by the General Contractor's Superintendent 90 h . . . c/jj^z fc£5c£> £ e c . / y fo . ~ ~ . — - • a Figure 4.1.5 Schedule Made in November 1999 (the First of Three-Page Schedule) by the Forming and Concrete Placing Subcontractor's Superintendent 91 In terms of project execution, excavation started on June 23, 1999, and occupancy of the commercial component had to be achieved in early August 2000. The completion date was tied to a preset opening date of the London Drugs Store. Typically, the way schedule issues were handled on an ongoing basis was to set target dates for various parts of the substructure, and then push to get there. What this often meant is that work was performed on an opportunistic basis - i.e. if work was available in a given area, or if by changing the sequence, work could be made available, it was done, even if the work was not critical. In terms of construction methods employed during the time period studied, no novel methods were observed. As noted previously, the construction strategy for both the excavation and shoring as well as the substructure evolved as familiarity with the plans grew, as the project was manned up, and as accommodations had to be made with other projects. With respect to the latter, the excavation subtrade was coordinating work on this site with another one in downtown Vancouver that needed good quality fill. Since the geotechnical profile indicated good quality sand on various parts of the site of the Kerrisdale project, the excavation pattern at times appeared to the uninformed as somewhat haphazard. This was an example of where the optimum solution for a firm (in this case, the excavation subtrade) for its portfolio of projects did not correspond to the optimal solution for a single project. The Microsoft Project Schedules were made in the general contractor's central office. Neither superintendent made direct use of them, nor did they have a computer on site. 92 4.2 Updating The research schedule was updated from time to time to facilitate the comparison of actual performance with planned performance. Although the duration of each activity could be compared with its planned duration, this did not give an accurate picture of actual performance. Because of a clear understanding of what a delay on an activity meant to the complete project plan, it was necessary to perform a complete update by updating actuals as of a certain date, recomputing the schedule, determining where modifications are needed (scope, sequences, duration) making these modifications, recomputing the schedule, then monitoring performance against it. Updating done at the end of August 1999 showed what would happen if the as-planned schedule had not been followed (see Figure 4.2.1). The excavation work was being done out of sequence with no particular strategy readily apparent. As noted previously, one of the reasons for this was that the excavation subcontractor coordinated work on this site with another one in Downtown Vancouver that needed good quality fill. Excavation and almost all of the shoring work should have been finished by the end of August according to the planned schedule. Instead, excavation was still ongoing on the East side, and shoring had not been completed on both the West and East sides. This situation, if left as is, would have led to disastrous results as shown in the updated schedule (Figure 4.2.1) with the ground floor not being completed until the end of February. The projected duration for the schedule updated on August 31 was 274 calendar days for the scope of work treated. Compared to the original UBC schedule, the construction of the substructure would thus have been delayed by some 53 calendar days. 93 It should be noted that once the 7-stage construction schedule was developed, the research team did not try and modify its logic to bring the project back into line. Instead, the same schedule was kept and actuals were entered in order to monitor project performance. Figure 4.2.1 Construction Schedule Updated as of August 31,1999 94 The last update was done on November 5, 1999, which was the last day of the 20-week period of the detailed daily data collection. The duration for the scope of work examined became 228 days as of that data date. Based on this update, the ground floor was forecasted to be done by January 13, 2000 which was 46 days earlier than the completion date obtained by updating on August 31. The main reason for such a difference was that in mid October, the Kerrisdale Station Project was accelerated through the use of 10 to 12-hour working days and by working Saturdays. The actual as-built date when the ground floor was completely finished was January 18, 2000 which gives the total duration for the construction of the substructure as 233 calendar days. With the difference of 3 calendar days between planned schedule updated as of November 5, and the actual completion date of the work treated, it is noted that the UBC schedule was pretty accurate. Table 4.2.1 gives different durations of the Kerrisdale substructure construction for different schedule models in terms of pour stages and different update dates. Number of stages Update as of Duration in calendar days 2 23-Jun-99 205 3 23-Jun-99 236 5 23-Jun-99 222 6 23-Jun-99 229 7 23-Jun-99 229 7 31-Aug-99 274 7 30-Sep-99 249 7 30-Oct-99 221 7 5-Nov-99 228 8 Actual duration 233 Table 4.2.1 Duration for Various Numbers of Planned Stages and Different Update Dates 95 4.3 Monitoring Computer modelling of projects brings new possibilities for capturing data at the site. The trick is to design software which is easy to use and which encourages site personnel to record the as-built story using the software as opposed to traditional manual ways. As part of the case study and thesis work, one of the objectives was to test and further refine a site reporting system that had been developed as part of an ongoing research program. Refinement included converting the reporting system to Windows and adding additional functionality for viewing project data. Another objective of the research was the collection of reliable site data in electronic form, which could later serve as the platform for modelling the construction process, productivity estimating and analysis, and for cause and effect relationship analysis. The status of construction activities, on-site equipment usage, materials delivered and stored, job-site visitors, site conditions, and etc. were all be recorded on a daily basis. Daily data were collected using the REPCON5 daily site form (see Figure 3.2.2 The REPCON5 Daily Site Form - General Project Data and Activity Information). 96 4.3.1 Daily Site Reporting Data Entry - the As-Built Views Daily Site Data PR0.I41 \7STGSD Eie Ed* Help Activity Code 010600 010800 010900 011000 011100 011200 011300 "011400 020800 020900 021000 "022100 "022300 022500 022500 022600 0^22700 Ste Environment Data Loc Information/Activity Description Site Environment Data Dairy Work Force Data Survey Works Inspections Visitors Safety Log !• Accidents Site Instructions Daily Deliveries Blasting Dairy Ecjipment/Rentals Miscelaneous Notes Remove access ramp Bulk excavation • East Excav perimeter strip Itgs - E Excavate core lootings - E Excav col/int wel ftgs - E BackiB cores/ftgs-West side Backfill cores/ftgs-East side Excavate crane footing • East F/R/P/C/S col ftgs-E side F/R/P/C/S ext wal ftgs-E side F/R/P/C/S core ftgs - E side F/R/P/C/S tower crane ftg-East Erect tower crane • East side F/R/P/C/S Pkde WaHs - stage 1 F/R/P/C/S Pkde Wafe • stage 1 F/R/P/C/S Pkde cob - stage 1 F/R/P/C/S Pkde cores • stage 1 SEP SEP SEP 27 28 29 MON TUE WED SEP OCT OCT OCT OCT OCT OCT OCT 30 1 2 3 4 5 6 THU FRI SAT SUN MON TUE WED THU SITE P3 FDN FDN FDN FDN FDN FDN FDN FDN FDN FDN SITE P3 P2 P2 P3 GZD y y • y y y • • y • y • • y V y y y • y y • y y y o 1 O 1 0 1 0 1 0 1 o 0 0 1 O 1 0 1 0 1 0 1 0 1 0 1 0 1 o 0 0 1 0 1 O 1 o I 0 1 0 1 0 1 o 0 o 0 0 1 0 1 0 1 o 1 o 1 O 1 0 1 0 1 o 1 o 0 0 1 0 1 o 1 O 1 0 1 0 1 o 1 o 0 0 1 o 1 0 1 o 0 o 0 o 0 o 0 o 0 o 0 o 1 O 1 0 1 s S o 1 o 1 o 0 o 0 o 0 o 0 o 0 o 0 o 0 0 1 o 0 o 0 o 0 o 0 o 0 o 0 o 0 s IS o 0 o 0 o 0 o 0 o 0 o 0 o 0 s I S o O o O o O o 0 o 0 o 0 o 0 f F d D s is o 0 o 0 o 0 o 0 s IS o 0 o 0 o 0 f F for MONDAY. 27 SEP 1999 '2T\ | D aily S ite Data-PR 0J 4n7S T GSD | Figure 4.3.1 REPCON5 Daily Data Report Sheet The main daily site reporting system (as-built view) interface is shown in Figure 4.3.1. A check sign in the upper half indicates that data pertaining to this aspect of overall project context have been entered. The system presents those activities which are expected to be active for the time window chosen, based on the as-planned schedule. Further data are noted for each date against these, or other selected activities, indicating planned status in terms of the lower case descriptors s, o,f, d, and blank field. These descriptors are defined as follows: V for started, "o" for ongoing, "f for finished and V for started and finished (done in the same day), and blank 9 7 cell for no status. Upper case letters stand for actual - as-built activity status, which were tracked and entered on daily basis. As-built status has two more states than as-planned status: "P" for postponed status (e.g. the activity was supposed to start on a particular day according to the as-planned schedule, but it did not) and "I" for idle status (on days when nothing was done on an activity that previously had been started but not yet finished). During the case study, the following suggestion from the user's point of view regarding entering activity status was made: Disable the ability to enter the following activity status combination: Status F prior to the statuses S, O, I, or P Status / prior to the status S Status S, O, I, or P after the status F Status P after the status S, O, F, or I Status S after the statuses O, F, or / Status P prior to as planned status s More than two SOTF statuses for the same activity during its duration. 4.3.2 The REPCON5 Site Conditions Window Figure 4.3.2 shows the Site Conditions Window. Data for the upper half of this window were obtained from the daily newspaper (the Vancouver Sun) or from the web site: http ://weather. ec. gc. ca/forecast/yvr. html - Environment Canada Weather Forecast for Vancouver. 98 Weather data could be pulled from the web site and insert into files every few days. If the site personnel is not willing to do this, the requirement for everyday environment data could be omitted except for when extreme values appear (values that can cause construction impediments and delays), e.g. temperature < 5 °C, or > 25 °C, humidity > 80%, precipitation > 10 mm, wind velocity > 30 km/h. Further, it is suggested that humidity data be included in the daily site reporting as a part of the site conditions (for more details see section 4.3 and 4.5). Daily Site Data-PROJ4f \7STGSC Activity Code 010600 010800 010900 011000 011100 011200 011300 020800 020900 021000 022500 "022500 022600 022600 022700 022700 022900 Site Environment Data Loc Information/Activity Description Site Environment Data Daly Wo* Force Data Survey Works Inspections Visitors Safety Log & Accidents Site Instructions Daily Deliveries Blasting Daily Equipment/Rentals Miscelaneous Notes Remove access ramp Bulk excavation • East Excav perimeter strip ftgs - E Excavate core footings - E Excav col/mt wall ftgs • E BackfiS cores/ttgs-West side Backfill cores/ftgs-East side F/R/P/C/S col ftgs • E side F/R/P/C/S ext wall ftgs-E side F/R/P/C/S core ftgs • E side F/R/P/C/S Pkde Walls - stage 1 F/R/P/C/S Pkde Walls - stage 1 F/R/P/C/S Pkde cols - stage 1 F/R/P/C/S Pkde cols • stage 1 F/R/P/C/S Pkde cores • stage 1 F/R/P/C/S Pkde cores - stage 1 F/R/P/C/S Pkde susp slab-stg 1 OCT OCT OCT OCT OCT OCT OCT OCT OCT OCT OCT * . 18 19 20 21 22 23 24 25 26 27 28 MON TUE WED THU FRI SAT SUN MON TUE WED THU — SITE P3 FDN FDN FDN FDN FDN FDN FDN FDN P2 PI P2 PI P2 P1 PI y y y y y y y y y y y y y y y y y y Jite Conditions for WEDNESDAY. 27 OCT 1999 AM Sky Coreftion r Dear <~ Rain <~ Snow Temperature (C): AM PM Ground Condition Storage on Site t~ Good (~ Good <• Fair <*• Fair <~ Poor (~ Poor PM Sky Condition C Clear f Cloudy P Rain <~ Snow Precipitation (mm): f?9 Wind (kph): Access to Site C Good f Fair r Poor [33 Effects C None f Minor «• Significant OK "J Comments Remove Cancel forWEDNESDAY. 27 OCT 1999 s IS o 0 o 0 o 0 o I o IO s IS o 0 o 0 o 0 0 IO o "0 o 0 o 0 F M ' • ' IT Figure 4.3.2 REPCON5 Site Conditions Window Ideally, as indicated previously, all data sought should be quantifiable in numerical form using objective and reproducible measurement techniques. This is not possible, except for selected weather data and manpower counts. Instead, both researchers and site personnel were faced with making subjective assessments on various site condition parameters in terms of 9 9 linguistic, as opposed to numerical values. As seen on the Figure 4.3.2, ground conditions are expressed as good, fair, or poor, with additional commentary to describe specific features. It was not always possible to achieve a consensus amongst members of the research team on the appropriate values. From time to time, the research team consulted with site personnel about their assessment of non-measurable data. A typical problem in making a subjective assessment was that site conditions on one part of the site were fine, but on another part, where there was water, conditions were poor. Again, the research team judgement was used to estimate if conditions were poor, fair or good. Similar problems plagued site personnel for their own reporting. 4.3.3 The REPCON5 Work Force Window As indicated in Figure 4.3.3, the number of supervisors, number of workers and number of traffic controllers can be recorded for every workday, for each trade, including the general contractor. In addition, there is a check box for expressing a judgment as to whether or not sufficient personnel were in attendance for the work available. Also, the facility exists to comment on the work force skill level and turn over. An accurate manpower count was not difficult to achieve when there were only a few ongoing activities at the same time at site. However, when forming and concrete placing activities (for column footings, columns, walls, and slabs) were ongoing simultaneously, the research team faced a problem with reconciling conflicting opinions about the work force count. For example, none of the construction workers from the forming and concrete placing subcontractor was assigned to only one task during a typical 8-hour working day. Very often, one worker carried out several different tasks on the same day, and even having two recorders on site was insufficient to track accurately labour usage. Some difficulties in the work force count 100 were avoided by asking the subcontractor superintendent. However, the level of detail pursued by the research team was very often beyond the subcontractor superintendent's data. He did not allocate labour hours against cost codes. He simply filled out a time sheet for payroll on a daily basis. In addition, it was difficult on a large and congested site to observe all the workers that were involved in construction activities. Worker crossover from one work area to another also distorted the results. Research team faced another difficulty in expressing a judgement about the sufficiency and skill level of management's personnel and each trade's work force. Often, the same events were described in different ways by different members of the research team. Daily Site Data-PROJ41\7STGSD Activity Code 010600 010800 010900 011000 011100 011200 011300 020800 020900 021000 022500 "022500 022600 022600 022700 022700 022900 j ] Dairy Work Loc I nf of motion/Activity Description Site Environment Data Daifci Work Force Data Survey Work* Inspections Visitors Safety Log & Accidents Site Instructions Daily Deliveries Blasting Daily Eouipnrientvflentals Miscellaneous Notes SITE Remove access ramp P3 Bulk excavation • East FDN Excav perimeter strip ftgs - E FDN Excavate core footings - E FDN Excav coVint wall ftgs - E FDN Backfil cores/ftgs-West side FDN Backfl core*/Ttgs€ast side FDN F/R/FVCyS col ftgs • E side FDN F/RtfVC/SextwaIftgs€side FDN F/RAVC/S core ftgs - E side P2 F/fl/P/C/S Pkde Wals - stage 1 P1 FM/P/CJS Pkde Wats- stage 1 P2 F / R A V C S Pkde cols - stage 1 P1 F/Tl/P/C/S Pkde cols - stage 1 P2 F/R/P/C/S Pkde cores • stage 1 PI F/R/TVC/S Pkde cores • stage 1 P1 F/R/P/C/S Pkde susp siab-stg 1 OCT OCT OCT OCT OCT OCT OCT OCT OCT OCT OCT 18 19 20 21 22 23 24 25 2G 27 28 MON T U E W E D THU FBI SAT SUN MON TUE W E D THU • • < • • • • • • • • • • • • • • jSeiecf Hem... X] I O I Date: 180CT99 ' Work F orce for MONDAY. M OCT 1 999 ResponsibSty Code: III H G 1 02 1 04 1 05 1 06 1 01 0 Edit 0 , F M Trade: Formwork Number of Supervisors: |1 Number of Workers: W Number of Traffic Controllers: Ski! Level t* High <~ Medium I Low 17 Sufficient TurnOver r High <~ Medium & Low Over Time Hours: |l.00 Force Data for MONDAY. 18 OCT 1999 Figure 4.3.3 R E P C O N 5 Work Force Window 101 4.3.4 The REPC0N5 Survey Works Window Survey work is allocated against the Responsibility code and the Number of crews involved. It is assigned against the activities for which it was performed and the relevant physical location. A comment field allows the user to describe any additional data that could not be entered in the above data fields (see Figure 4.3.4). Such data was sometimes difficult to collect. Survey work for a particular activity always lasted less then a few hours, most often less then an hour. Hence it was not easy to track. mum OCT OCT OCT OCT OCT OCT OCT OCT OCT OCT OCT information/Activity Description 18 19 20 21 22 23 24 25 28 27 28 HON TUE WED THU FBI SAT SUN MON TUE WEO THU Site Environment Data • y V • • Da3y Work Force Data • y y y y y • • Survey Works Inspections {^ flggBHlWBHBB Visitors _ 1 • f l 010600 010800 010300 011000 011100 011200 011300 020800 020900 021000 022500 "022500 022600 022600 022700 022700 022900 Survey Works Safety Log & Site Iratructk Dairy Detveri Blasting DafeiEquipm Miscelaneou SITE Remove acc P3 Bulkexcavat FDN Excav perirra Date: 260CT99 Survey Works lor TUESDAY. 2G OCT 1999 ±1 Location! FDN Responsibilty Code: Trade: Formwork Number of crews: Locations "3 Activities Ed* FDN F/R/P/C/S col ftgs - E side FDN F/fi/P/C/S ext wal ftgs-E side FDN F/R/P/C/S core ftgs • E side P2 F/R/P/C/S Pkde Wals • stage 1 PI F/R/P/C/S Pkde Wals • stage 1 P2 F/R/P/C/S Pkde cots • stage 1 P1 F/R/P/C/S Pkde cols • stage 1 P2 F/R/P/C/S Pkde cores • stage 1 PI F/R/P/C/S Pkde cores • stage 1 P1 F/R/P/C/S Pkde susp slabstg 1 FDN "3 &dd I 3 Add Comments Survey for column footings. OK for TUESDAY, 26 OCT 1999 Figure 4.3.4 R E P C O N 5 Survey Works Window ^3 Remove Cancel I Crystal SRS 3D* 102 4.3.5 The REPCON5 Inspection and Safety Log Window Data regarding inspections, safety log, and accidents at the site are associated with locations and also have the comment field. The inspection data window is shown in Figure 4.3.5. Similar to survey works, inspections lasted less then an hour, but were easier to track because the research team could obtain the inspection paperwork from site personnel. Activity Code 010600 010800 010900 011000 011100 011200 011300 "011400 020800 020900 021000 "022103 "022300 022500 022500 "022500 022600 Inspections Loc Information/Activity Description Site Environment Data Daiy Work Force Data Survey Works Via Saf Date:260CT99 Sic Dai Sta: Dai Mis SITE Rer P3 Bull FDN Exc FDN Exc FDN Ext FDN Bac FDN Bac OCT OCT OCT OCT OCT OCT OCT OCT OCT OCT OCT 21 22 23 24 25 26 27 28 29 30 31 THU FBI SAT SUN MON TUE WEO THU FBI SAT SUN • • • • • • • • • • • • • ; _ V L... Comments P2 RJC • reviewed reinforcement for level P2 to PI parkade ramp at 31 New Remove Close o 0 o I o 0 o I o I o 10 o 10 o 10 o I I !0 FDN Excavate aar» footing • East FDN Pm/PKJZ col ftgs - E side FDN F/WP/CS ext wall ftgs-E side FDN rm/PtUS core ftgs • E ade FDN F/RAVC/S tower crane ftgtast SITE Erect tower crane-Eastside P3 fm/PfUS Pkde WaJs - stage 1 P2 F/R/P/C7S Pkde Wals - stage 1 PI m/P/US Pkde Wats- stage 1 P2 rm/P/OS Pkde cob • stage 1 (or TUESDAY. 26 OCT 1999 Inspect ions for TUESDAY. 26 OCT 1999 location: Ife _J Comments RJC • reviewed reinforcement for level P2 to P1 parkade ramp at 3 to 4 to E. also for cols. ! from P2 to P1 at line E^.6.7. and F/6 mmmmmmammKLmm OK Remove | Cancel Figure 4.3.5 REPCON5 Inspection Window 4.3.6 The REPCON5 Daily Deliveries Window The daily deliveries window, shown in Figure 4.3.6, describes the items delivered, quantities, units, and comments if any. 103 The main difficulty in tracking deliveries was that many of them were for subtrades, and the construction management company did not monitor subtrade deliveries. When construction started, member of the research team monitored deliveries by simply observing the delivery trucks that arrived at site. Later on, when more activities and more subtrades were active at the construction site, it became difficult to obtain accurate delivery data, especially if the various subtrade superintendents were not available to share their information with researchers. . Daily Site Data-PROJ.4 Activity Code "010100 "010100 "010100 010800 010800 "010800 020100 020200 020300 "030200 070100 070100 070100 070200 070200 L O G inform. JUL JUL Activity Description 1 2 THU FRI JUL JUL JUL JUL JUL JUL JUL JUL 3 4 5 6 7 8 9 10 SAT SUN MON TUE WED THU FRI SAT JUL Jl 11 1 SUN Ml Date: 0BJUL99 P3 P2 P1 P3 P2 PI OFFS OFFS OFFS SITE P3 P2 PI P2 PI Site Environment Data Dairy Work Force Data Survey W f f l H B Inspector Visitors Safety Lo Site Instn, Daily Deli-Blasting Daily Equ MisceHam Bulk exec Bulk exec Bulk exes Bulk exca Bulk exci Bulk exca Jtem Quantity Unit Comments Ram Set 5.0 boxes Powder Fa; Makrta 5007NB 1.0 unit Saw for wo Concrete 6.0 m3 for shotcret MicrosH Anchor Grout 288.0 bags for grouting 1 M I o 10 o I Dehverres for THURSDAY. 08 JUL 1999 Prefab footing forms Prefab column forms Prefab wall forms Install dewatering - N side Instal anchors/shotcrete • W Instal anchors/shotcrete • W Install anchors/shotcrete • W Install anchors/shotaete - E Install anchors/shotcrete - E Item |toncrete Quantity: |6.00 Ur*. JmT Comments [ 3 for shotcrete OK Remove Dairy Deliveries for THURSDAY. 08 JUL 1999 Figure 4.3.6 REPCON5 Deliveries Window Cancel 4.3.7 Problem Sources To facilitate a standardized vocabulary, consistent and easy reporting of problems, and transfer of experience from one project to the next, the daily site reporting system supports the use of user-defined problem codes that are organized in a two-level hierarchy. The list developed 104 for the research project is presented in Table 4.3.1. A considerable portion of this list is based on previous experience gained on other projects. Identifying the problems that interfered with construction activities, as well as assigning the relevant time which was lost because of the problems encountered, brought new difficulties to the research team. Often, the same events were interpreted in different ways by different researchers. Also, the attitude of researchers often reflected the attitude of the management personnel, e.g. if their attitude was that the workforce possessed a low skill level, the researchers made less of a conscientious effort to be sure that observations were correctly recorded. From the user's point of view, researchers found that the 24-character field for problem descriptions was often not long enough to define the problem properly. Hence, it should be longer. Also, for deliveries data, a field for relevant trade and location delivered to should be introduced. 105 Problem Code / Description problem Code / Description |Problem Code / Description |01 W E A T H E R 01 Too much precipitation 02 Too little precipitation 03 Temperature too high 04 Temperature too low 05 Wind too high 06 Excessive humidity 07 Freeze-thaw cycle 02 SITE CONDITIONS 01 Insufficient storage space 02 Inadequate external access 03 Inadequate internal access 04 Congestion 05 Site not prepared / available 06 Poor ground conditions 07 Work space not cleaned 08 Excessive ground water 03 O W N E R & C O N S U L T A N T S 01 Decision required 02 Changes requested 03 Interference/stop work order 04 Extra work requested 05 Awaiting inspections/tests 06 Excessive quality demand 04 DESIGN / DRAWINGS 01 Drawing errors 02 Design changes / additions 03 Drawings insufl7incomplete 04 Conflicting information 05 Poor design coordination 06 Waiting for drawings 05 S C H E D U L E 01 Delay of activity predecessor 02 Work done out of sequence 03 Improper sequencing of activity 04 Delay of procurement 06 W O R K F O R C E 01 Undermanning 02 Overmanning 03 Low skill level 04 Excessive work force turn over 05 Low worker motivation 06 Inadequate instructions 07 Unsafe practices / accidents 08 Worker fatigue (long shifts) 09 Interference of other trades 10 Poor trade coordination 07 W O R K 01 Estimating error 02 Error in construction 03 Layout error 04 Poor workmanship 05 Rework due to design changes 06 Rework due to poor workmanship 07 Rework due to damage by others 08 Rework due to quality )^8 SUPPLIES & E Q U I P M E N T 01 Insufficient materials 02 Insufficient equipment 03 Late delivery of material 04 Late delivery of equipment 05 Tools / equipment breakdown 06 Damaged deliveries 07 Fabrication errors 08 Inefficient materials handling 09 UTILITIES / CITY 01 Awaiting permits 02 Awaiting connection 03 Awaiting inspections / tests 04 Interference of existing utilities 05 Damage of existing utilities 06 Unanticipated utilities 10 M I S C E L L A N E O U S 01 Theft 02 Strikes 03 W C B order 04 Delay/change in award of contr. 05 Noise level too high 06 Natural disaster Table 4.3.1 Problem Categories and Description 4.3.8 The REPCON5 Activity Work Force Data Besides assigning to an activity its actual status and any problems encountered each day, it is possible to record the labour and equipment usage involved in carrying out an individual activity. This feature is important when one wants to collect data at a more refined level of detail, 106 or address specific activity problems. Figure 4.3.7 illustrates entry of activity work force data while Figure 4.3.8 shows the assignment of equipment usage. Ble Ettt Help Activity Code 010600 010800 010900 011000 011100 011200 011300 020800 020900 021000 022500 Loc Information/Activity Description Site Environment Data Daily Work Force Data Survey Work* Inspections Visitors Safety Log & Accidents Site Instructions Daily Deliveries Blasting Daily Equipment/Rentals Miscellaneous Notes Remove access ramp Bulk excavation - East Excav perimeter strip ftgs • E Excavate core footings • E Excav col/int waB ftgs - E Backfill cores/ftgs-West side Backfill cores/ftgs-East side F/R/P/C/S cd ftgs • E side F/R/P/C/S ext was ftgs-E side F/R/P/C/S core ftgs - E side F/R/P/C/S Pkde Walls - stage SITE P3 FDN FDN FDN FDN FDN FDN FDN FDN P2 oi OCT 17 SUN OCT 18 MON V OCT 19 TUE V' OCT 20 WED <S OCT 21 THU V OCT 22 FRI OCT 23 SAT OCT A 24 • SUN Daily Status Data for TUESDAY. 19 OCT 1999 cto 10imc o i . - u > . . t ~ . » Activity. 021000 Status I Problems at location FDN Work Force F/R/P/C/S core ftgs-E Equipment Responsibility Code: 02 Number of Supervisors: Number of Workers: [4 Number of Traffic Controllers: f Skill Level j C Low (~ Medium ; High Trade: Formwork P Sufficient Turn Over i* Low C Medium f High Over Time Hours: | 021000 : F/R/P/C/S core ftgs • E side for TUESDAY Figure 4.3.7 REPCON5 Daily Status Data - Work Force Equipment data can be associated both with the overall project and with individual activities (see Figure 4.3.8). The status of usage of an individual equipment item can be recorded as: Delivered (the day when the piece of equipment arrives at site) Active (if the piece of equipment was used that day on the activity) Idle (if the piece of equipment was at site but not involved in the construction process) 107 . Daily Site Data PH0J4n?ST6Sf) Activity Coda 023600 023700 023900 023300 024000 024100 024200 024300 024400 024500 024600 024600 '024700 024700 024800 024900 025000 025100 "025200 025200 025300 025500 050500 050600 050800 070200 070200 070200 Loc Information/Activity Description P2 F/R/P/C/S Pkde cob • stage 3 P2 F/R/P/C/S Pkde cores • stage 3 P2 F/R/P/C/S Pkde susp slab-stg 3 PI F/R/P/C/S Pkde susp slab-stg 3 P2 F/R/P/C/S Pkde WaHs - stage 4 P2 F/R/P/C/S Pkde cots - stage 4 P2 F/R/P/C/S Pkde cores • stage 4 P3 Prep/F/R/P/C/S S0G - stage 4 P2 F/R/P/C/S Pkde susp slab-stg 4 P3 F/R/P/C/S Pkde Wab - stage 5 P3 F/R/P/C/S Pkde cols - stage 5 P2 F/R/P/C/S Pkde cob - stage 5 P3 F/R/P/C/S Pkde cores - stage 5 P2 F/R/P/C/S Pkde cores-stage 5 P3 Prep/F/R/P/C/S SOG - stage 5 P2 F/R/P/C/S Pkde susp slab-stg 5 P3 F/R/P/C/S Pkde Wab - stage 6 P3 F/R/P/C/S Pkde cob - stage 6 P3 F/R/P/C/S Pkde cores - stage 6 P2 F/R/P/C/S Pkde cores • stage 6 P3 Prep/F/R/P/C/S SOG • stage 6 P2 F/R/P/C/S Pkde Wak - stage 7 FDN Trench (or U/G wet uS-East FDN Install U/G wet utilities-East FDN BackflU/G wet utj- East P3 Instal anchors/shotcrete - E P2 Instal anchors/shotcrete - E _RJr^atanchw$/sl^ete^ OCT OCT OCT OCT OCT OCT OCT OCT OCT OCT OCT 1 18 19 20 21 22 23 24 25 26 27 28 MON TUE WED THU FRI SAT SUN MON TUE WED THU s IS o 10 s IS o 10 s S o 0 o 0 o 0 f F t IS Daily Status Data foi TUESDAY. 19 OCT 1999 Activity: 070200 Instal anchors/shotcrete - E at location P2 Status | Problems j Wotk Force Equpment | Item Quantity Status EQUIPM_.Dri«rig 1.0 A EQUIPM_.Compressor 1 0 A EQUIPM .Shot pump 1.0 A EQUIPM .Mixer 10 A EdJItem Add Item Remove item OK Remove Cancel 070200 : Instal anchors/shotcrete - E for TUESDAY. 19 OCT 1999 Figure 4.3.8 R E P C O N 5 Daily Activity Status Data - Equipment Returned (the day when the piece of equipment is transported off the site) No Status (when no information was recorded about the piece of equipment involved in the construction process). Collecting equipment data proved to be relatively easy task for the research team. The only problem occurred when assigning a status to a piece of equipment that was involved in an activity for only a part of a workday and the rest of the day it was idle. That problem was solved by assigning either ongoing, or idle status accompanied with appropriate commentary. However, this issue highlights the challenge of accurately recording the events of a day. For example, our experience on the Kerrisdale project research showed that one piece of equipment could arrive at site and leave in the same day. Hence, the suggestion is to have an option Delivered and Returned status for equipment in the daily status data window, e.g. the mobile crane was delivered and returned on the same day (for the tower crane erection). 108 4.4 Reporting and Data Representation Reports from the daily site reporting module are available in both graphic and text forms. As part of the work, enhancements were made to the reporting feature, especially in the area of graphics (3D vs. 2D) to facilitate visualization of the data. Daily site data at the Kerrisdale Station Project were tracked for the period from June 23, 1999 to November 5, 1999. This represents a total of twenty weeks or 136 days of daily data. Once daily site data were entered, various reports were created. A challenge for construction personnel is how to extract messages embedded in the data. Members of the research team found the use of graphical images and text reports to be very helpful in this regard, as described in the following text. 4.4.1 Activity Status Figure 4.4.1 shows a 3-D depiction of the status of the bulk excavation activity versus time and work location. It can be seen readily that the bulk excavation activity on the West side of the site was idle for a considerable number of days. The reason for this recurring state was that the excavation subtrade was coordinating work on this site with another one in downtown Vancouver that needed good quality fill. Since the geotechnical profile indicated good quality sand on various parts of the site of the Kerrisdale project, the excavation pattern at times appeared to be somewhat haphazard. Also shown through shading (normally in colour on the screen) are various problem codes on the days that problems were experienced. A priority system exists such that the problem code of greatest interest to the user is highlighted when more than one problem is recorded for a given day. Problems encountered are described in more details in following section. 109 Statu* ot 010100 Bulk excavation - Wow Problem Code Profile: Bufc_We«t Figure 4.4.1 Status of the Bulk Excavation on West Side Activity 4.4.2 Problems Encountered During the time period for which data were collected, 22 different problem sources were encountered. They are shown in Table 4.4.1 and some of corresponding data are represented visually in Figures 4.4.2, 4.4.3, 4.4.5, 4.4.7, and 4.4.8. Difficulty is often encountered in estimating the consequences of a problem in terms of manhours lost or time lost on an activity-by-activity basis. One has to rely on the experience and judgment of seasoned site personnel. For this research, the site observers made the judgments and consulted from time to time with site personnel. It should be noted that time lost corresponds to time lost on a particular activity. This does not necessarily translate into a lengthening of the overall project, unless the activity is critical. 110 Problem Code Problem Description Time Lost Number of Frequency1 Manhours Days Occurrences 1.5 Wind too high 498.0 24.00 97 30.22% 1.1. Too much precipitation 177.0 12.90 70 21.81% 2.4 Congestion 150.0 8.80 63 19.63% 2.6 Poor ground conditions 71.0 4.85 25 7.79% 2.8 Excessive ground water 25.0 5.70 14 4.36% 4.6 Waiting for drawings 35.0 3.25 9 2.80% 2.3 Inadequate internal access 7.0 1.70 9 2.80% 8.5 Tools/equipment breakdown 29.0 1.40 7 2.18% 6.10 Poor trade coordination 136.0 4.50 6 1.87% 1.3 Temperature too high 12.0 0.40 4 1.25% 7.8 Rework due to quality 10.0 0.50 3 0.93% 8.1 Insufficient materials 27.0 0.80 2 0.62% 8.4 Late delivery of equipment 2.00 2 0.62% 8.3 Late delivery of materials 0.70 2 0.62% 5.2 Work done out of sequence 6.0 0.15 1 0.31% 4.2 Design changes/addition 2.5 0.10 1 0.31% 3.2 Changes requested 2.0 1.00 1 0.31% 8.8 Inefficient material handling 2.0 0.20 1 0.31% 6.2 Overmanning 0.30 1 0.31% 8.2 Insufficient equipment 0.30 1 0.31% 6.5 Low workers motivation/morale 0.25 1 0.31% 6.3 Low skill level 0.20 1 0.31% Table 4.4.1 The List of Problems Marked During the Daily Site Recording in Period From 23/June/1999 to 5/November/1999 It is possible to integrate over one or more activities, over all the activities of a trade, over multiple trades, and so forth for a user-specified time window to generate a plot of the number of problems, manhours lost, or time lost versus location and problem code, as shown in Figure 4.4.2. Such a visual representation of data helps to explain the reason for construction delays and can contribute to the identification of relevant corrective actions. 1 Frequency stands for the percentage of occurrences for each problem code against the total number of occurrences for all problem codes against all activities affected - e.g. if 10 activities were affected by high wind on 10 days, then the number of occurrences would be 100 111 Problem status by ptoblem code, location Pioblem Piodle foi Activity Pi otile: All ActMIfes Date: 2SJUII99 to OSIIOVM PROBLEM CODE LOCATION 1.1 Too much prectptotjon 2£ Poor ground condtions 52 Work done out ot sequenc 6-4 Late deSvery of equtpme 1 3 Temperature too high 1.5 Wind too high 2.3 Excessive ground water 3.2 Changes requested 5.10 Poor trade r^ x*cBnatJon 7.8 Rework due to quality 8.5 Tools/equipment breakdow 8.8 Inefficient materials ha 2.3 Inadequate internal acce 4.2 Design crtangesJeddWons 8.1 insutfictent materials 2.4 Congestion 4.6 Wading tor drawings 8.3 Late delivery of Zoom PQ Axis £rint Figure 4.4.2 Problem Status by Problem Code and Location for All Activities Shown in Figure 4.4.3 are the number of problems of different types recorded, manhours lost and days lost for the entire project (all trades). The most significant problems encountered were too much precipitation (1.1), and wind too high (1.5). Similar plots can be generated for each trade, and the user can specify the time window of concern. As noted at the beginning of this section, reports from the daily site reporting module are also available in text form. An excerpt from a text report on problems by problem or responsibility code for a selected time period is shown in Table 4.4.2 . Time lost estimates were provided by members of the research team. A complete listing of problems encountered during the 136-day observation period is provided in Appendix 2. 112 Q I tl a g. g. m O £ o n aC oC *£ a • o to je H H n ^ 3 •- IS « £ -g ° -2 S - . I_ «V —« l_> •n o u 9 t? a. *S -S | - ~ -*£ < 3 < O O O O C> O O O O OOOOOOOOOOOOOOOOOO o o o o o c» o o o o o g g g g g g g g g g g s 8 S S g g S S S S g g S S S 8 S g g S g g s s s s g 15 j i j 1! I I n l § 111111 I f f f 1 l l l l i l l l l l l l l i l l I s f f s f f § 11§s ^.^-o«f-»**^MU* « «, -5 —• — «•»«»-» m «-» *» *i •a o> •>«••* vi t "O TJ — «v C7» CT* or *uma« •> v *a ID U «l M D< •> < Ul •> •-> "O <y .-" CT« T7>«rO> bl kl U J T I i n « « i X ciki *)n*o ««n»«t j i« i j i«D>i v j i I , — er» . 21 -5 « * w • — u. « «« i . -^«^.t7>^«_c7-i « « « — • «. « r> « M U J «O «O » —• •> —' — — ~ «n o~ Ul —• • t t-i n Cr- •> « ul C7» « —< —• i •*>• • •» —• — w 5 ** ' « a.— " " ^ o t •> n « —« o. a. —< •»••—•••• — 7a  .   U I o a   '  <   m . 0> at •» i O*  • • tm-* CT- «- *V *t —< « U a" 1 " 3 U *J « • _ ' _ t± c u t e rin-i-Hu^cv-i i <«-t « *» *> < « « • 3 _« «> . —._.—•-> o —• «•» •/> H . a. — *> •» —•*'•»_ r * * , t ; . . . i 3 2 S ! , , ' > ^ ^ * ' > ^ . . . w o +.* C o o ~* xz * 1- c i- o x oxj^^ij<^<jit_»>^xxur3 •9 a-4 wua>a>auu •« <•» « o —. o o o *> ua.o.o<PiOia> >.p.a,e.>>. S —. t/» t/> t/» </•> »/l =S <Ohi —• W»1MWMWW»1I«NV1W11»;0 > > 1 S I S S S S , « 3 1 I > > > » S S^^a!«£«2q « 1 u U u i xx—. — — —» d m d x x x-• •—. a t a. ^  m a. °* i3 *•*c ^ * * > * s w * " — _. 3 -3 a o o o < o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o S S o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o 11 Table 4.4.2 Excerpt From the REPCON5 Daily Site Problem Sources Report Figure 4.4.3 Number of Problems, Total Manhours and Time Lost for the Whole Project 114 Figure 4.4.4 shows the number of poor ground conditions occurrences for excavation and shoring activities. The graph is plotted against dates and locations. Poor ground condition problem occurred 25 times during monitoring period and caused a 5-day time lost. Single problem status by date, location S O EI Figure 4.4.4 Problem Status for Poor Ground Conditions for Excavation and Shoring Activities Figure 4.4.5 depicts the kind of site data recorded using the daily site system and how it can be displayed. Shown in this figure are precipitation, temperature and wind speed versus time. This information is also available in tabular form as shown in Table 4.4.3 (A complete table is provided in Appendix 2). By overlaying this information with other data, it is often possible to explain events such as absenteeism of the work force. Figure 4.4.6 (a) shows the total manpower count for all trades including the general contractor, and also indicates the number of supervisors and traffic controllers present. Figure 4.4.6 (b) shows the manpower counts for the forming subtrade. Most of the variability in the forming trade manpower counts were due to two 115 Figure 4.4.5 Precipitation, Temperature, and Wind Speed vs. Time a a S o •s X X X X X X X X X X X X X X X X X X X X X X » x x x x x x x x X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X : x x x x x x x x x x x x O O O O O O O O O O O O O O O O v O O O t OOOOr~rv«000< a ,>0<»0< X X X X X X X : x x x x t O v O O O • >*nOOOOOOOOOOO< X X X : X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X » X X X X X X X X X X X X X X X X X X X X > o o o o o * 1 o o o o o . Table 4.4.3 Excerpt from Work Environment Daily Site Report i 80 60 Work Fores Size for whole project 8 8 8 s § § 1M Traffic Controlers Supervisors Workers : ""loom j Enrt Close | | J Figure 4.4.6 (a) Work Force for Whole Project Work Force Size for Reap. Code 02 - Formwork i 4 [ Traffic Controllers Supervisors Zoom J lCIMZll a - |j Figure 4.4.6 (b) Work Force for Formwork Trade reasons: concrete slab pours and weather which led to some absenteeism. An excerpt from the work force textual report which shows labour usage of selected responsibility codes is shown in Table 4.4.4 (A complete table is provided in Appendix 3). On several occasions, wind had a significant effect on the construction productivity. In particular, airborne foreign matter and wind force negatively influenced the construction progress. Airborne foreign matter blown about by the wind consisted of dust and/or wind-driven rain, and impaired the vision of workers, which in turn slowed their work output. Strong winds (over 30 km/h) caused the shut down of construction because one tower crane, and later two tower cranes, working in such conditions would have created significant safety issues. From Figures 4.4.5 and 4.4.7, it can be seen that relatively high wind speeds were experienced on at least three occasions. As a result, the cranes were shut down on two of the three days (October 14 and 27). The crane shutdowns caused the shutdown of every activity on the site because of the safety issues. The crane(s) were intended to pull out any worker who needed help since an emergency vehicle could not approach the hole. Vancouver has a very mild climate. It is highly unlikely that the summer temperature exceeds 33 degrees Celsius, and winter temperatures are very rarely below 0 (See Table 4.4.5). Thus, adverse weather impacts during the period studied occurred only a few times. On several days, the temperature was above 30 degrees, and when combined with humidity, there was some adverse impact on construction performance. Workers complained about their lowered ability to concentrate on work. It was also noted that they became tired more easily and took short, unscheduled breaks more often. 119 Table 4.4.4 Excerpt From the REPCON5 Work Force Report 120 Figure 4.4.7 Number of Wind-Too-Strong Problems Occurred in Period from June 23 to November 5 In what follows, a brief description of the combined effects of temperature and humidity is given. 121 Jan] Febij Marl Aprji May.;j Junij janvij fevrif marsj avrtj nm\ jwnij Aug] Sep;| Oct:) Novij Decij Year! aout sept; oct novij dec: anuee jTemperature; j Daily Maximum (°C)i 57, 8.0 9.9 12 7 16 3 j! 19 3 21.7. :' 21.7; 18.4; 13.5 90: : i 6 1 13.5 j Daily Minimum (°C)j 0.1 1.4. 2.6; •i 4.9 7.9l! 11.0. -: 12 7 129 10. vi 6.4. •i 3.0 :1 _ -I... . 0.8; j Daily Mean (°C) 4.7j i 6.3 8.8 12.1 15.2 17.2 I 17.4: 10 0 6.0 3.5: 99 | Extreme Maximum! ! _ 15.3 18.4; 19.4: 25.0 30.4:1 30.6: 31.7: 33.3; 29.3)| 23 5 18.4:; 14.9; j Datei 981/21+ 986/27 960/25:|987/27; 983/29: 970/02: 961/13; "960709: 988/03;f 980/03 980/04 J980/26 1 Extreme Minimum^  | (°Q -17.8 -16.1 -9.4. 1 . -3.3 0.6;] . n r 3 9: 67 6 1 o.ol| -5 9 -14 3;! j 17.8; Date; Moisture j _950/14;|950/01ij955/04+;i951/19i! 954/01;; 976/01. 949/02; 937/28950/29; 984/31:985/27 968/29 Vapour pressure: 0.67; 0.73: 0.77;| 0.86' 1.05 (kPa) Rel Humidity -! 88; 88: 87 85 84 0600L p/o) 84i| 85; 91 91; 88! Table 4.4.5 Canadian Climate Normals 1961-1990 VANCOUVER INT'L A, British Columbia, 49°11-N 123°10-W/O 3m 1937 to 1990 According to the Environment Canada (http://vvww.qc.ec.gc.ca/meteo/docum the humidex is a Canadian innovation, first used in 1965. It was devised by Canadian meteorologists to describe how hot, humid weather feels to the average person. The humidex combines temperature and humidity into one number to reflect the perceived temperature. Because it takes into account the two most important factors that affect summer comfort, it can be a better measure of how stifling the air feels than either temperature or humidity alone. Humidity is the amount of moisture in the air. Relative humidity is the ratio of water vapour in the air at a given temperature to the maximum amount which could exist at that 122 temperature. On hot summer days, the higher the relative humidity, the greater the discomfort, since perspiration evaporates less readily and the body feels hotter and stickier (see Table 4.4.6). Guide to Summer Comfort (Environment Canada) Range of Humidex Degree of Comfort Less than 29 No discomfort 30 to 39 Some discomfort 40 to 45 Great discomfort; avoid exertion Above 45 Dangerous Heat stroke imminent Table 4.4.6 A Guide to Summer Comfort Temperature (Celsius) 18 20 23 25 28 30 33 Humidity (%) 70 20 23 28 32 37 41 Al 75 21 24 29 33 38 42 48 80 22 25 30 33 39 43 50 85 22 25 31 34 40 44 51 90 23 26 31 35 41 45 52 95 23 27 32 36 42 47 54 Table 4.4.7 Humidex for the Range of Different Temperature and Humidity Average humidity in Vancouver is in a range from 80 to 90. Thus, as observed from Tables 4.4.6 and 4.4.7 some discomfort is present even when the temperature is in the mid 20s. When humidity is above 85 %, temperatures that exceed 27 degrees carry a great discomfort during which exertion should be avoided. Hence, it is suggested that the humidity data be included in the daily site reporting system as a part of site conditions. Should a claim for weather damage or delay be necessary, measures such as the humidex become extremely important. 123 Precipitation was found to have a mild adverse impact on the planned schedule since the rainfall during the time period studied never lasted for longer than a few days. Had it lasted longer, it would have had a much greater impact on the excavation, shoring, underground activities and concrete placement work, because of the sensitivity of these activities to wet conditions. The site was never shut down because of the rain, but according to the daily site records, a total of 12.9 days were lost due to too much precipitation (see Table 4.4.1, and Figures 4.4.3 and 4.4.5). Time lost estimates were made by the research team. It should be noted that time lost corresponds to time lost on a particular activity. This does not necessarily translate into a lengthening of the overall project, since not all the activities were critical. Some delay was caused by congestion. Crowding occurred when more workers were placed in a given area than could function effectively. It caused lowered performance. Because of delays encountered during excavation, management tried to accelerate construction in October, knowing that the nice weather would not last. In mid October, construction was accelerated through the use of overtime hours and working Saturdays. In addition, the work on activities was overlapped, these being excavation for column footings, excavation for strip footings, formwork, reinforcement, concrete pouring, curing and stripping of column footings, strip footings, columns; earth trimming etc. This caused the work force count to become higher, especially for forming and concrete pouring crew (see Figure 4.4.6 (b)). Ideally, the lower limit is 10 m2 of work space per person; below this point, 50 percent more workhours are required to perform the same amount of work (Thomas, 1990). This corresponds to an inefficiency of 33.3 percent. Once work was accelerated, it was observed that on several occasions, much less then 10 m2 of working area per person was available. As it can be seen from Figure 4.4.8 and in the opinion of the research team, congestion was initially experienced when the first tower crane was erected on the West side of the site (August 23, 1999), but increased significantly once work was accelerated in October. 124 Although production became higher in absolute values (earth excavated/day, concrete poured/day), productivity was lowered because of the congestion created by the allocation of additional resources (see, for example, Figure 4.4.6 (a) and (b) which show the work force for the whole project and for the forming and concrete placing subcontractor). Single problem status by date, location Problem Profile for Problem Code: 2.4 Activity Profile: All Activities ****** * " a DATE LOCATION SITE FDN Zoom gate Axis Zoom Location Axis j| Print Close j j Figure 4.4.8 Number of Congestion Problems for All Activities in the Period from June 23 to November 5 Waiting for drawings was among the most emphasised problems besides congestion and weather factors. Seemingly, the general opinion of both the research team and management was that there were too many project changes caused by the owner, and this, combined with an undermanned architectural firm, resulted in the delayed issue of drawings. The possibility of pursuing impact costs was raised by the general contractor's vice president during one of the site meetings. 125 4.5 Enhancements to the Daily Site System The daily report forms available in the research system are suitable for research purposes, but the suggestion is that they be modified to meet better the requirements of projects and so that data can be more easily gathered by field personnel. The following suggestions are made to help make the user interface more accessible and friendly and to improve representation of daily site data. Consideration must be given to the fact that construction personnel are loath to write brief narratives of events on site. Very often, portions of the daily site report for different days are the same. Therefore, the possibility of introducing copy/cut/paste features would be beneficial to the user (e.g. copy the Work Force and Equipment data from the day before). Sometimes an ongoing activity does not appear in the time window selected, because work is done out of sequence. Therefore, allowance should be made to add manually an unscheduled activity, or to pull out the needed activity from the activity list, or to pick the needed activity from the drop-box which contains the list of all the activities of the project. To avoid inconsistencies in daily equipment data for general project and activity data levels, the suggestion is made to disable the possibility of entering pieces of equipment associated with single activities in the Daily Status Data Window if the piece of equipment is not listed in the general project data under the "Daily Equipment/Rentals" for the particular day, i.e. there should be a tie-in to the resource lists. In the deliveries window, allow a field for relevant trade and location delivered to. 126 For keeping track of the as-built quantities, or physical progress, it is suggested that allowance be made for entering daily performed quantities in a numerical (floating point) field of the Progress Remarks of the Activity Dairy part of the form. This requires some linkage between the physical process and as-built views of a project. To enable retrieval of all relevant information regarding meetings held at site, add the feature "Meetings at site" (date, meeting participants, comments). In addition, this feature should include the possibility of storing meeting minutes in scanned form, e.g. Adobe Acrobat. In order to reduce the data entry task, the requirement for accurate environment data could be omitted except for when extreme values appear (values that can cause construction impediments and delays) , i.e. temperature < 5 °C, or > 25 °C, humidity > 80%, precipitation > 10 mm, wind velocity > 30 km/h. It is suggested that humidity data be included in the daily site reporting as a part of the site conditions. For weather data required in the Site Conditions Window, system could automatically go to a user specific web site (e.g. http://weather.ec.gc.ca/forecast/yvr.html) every n days, pull off the relevant weather data and insert it into the system files. For a better understanding of construction progress, it is suggested that the ability be added to print the spreadsheet with activity status cells and with exclamation marks indicating the existence of problems that occurred for each activity on each day. To avoid typing errors that can lead to difficulties, spell checking should be included in the system. 127 Experience from the Kerrisdale project says that one piece of equipment can arrive at the site and leave the same day. Hence, the suggestion is to have an option "Delivered and Returned' status for equipment in the Daily Status Data Window, e.g. the mobile crane was delivered and returned in the same day (for the tower crane erection). In addition, pieces of equipment might be either active or idle. Sometimes, they can have "No Status" when there is not enough information about their involvement in construction activities, e.g. according to superintendent - on one day, the excavator was active for only 15 minutes, and idle the rest of the day. There is no graphics capability to depict the actual set of equipment plotted against time. The capability to draw as many plots as the number of pieces of equipment defined in the Resource Edit Mode should be included. Further, add the possibility of comparison plots of planned and actual set of equipment. Introduce comparison plots of planned and actual work force. To have a better picture of the daily site spreadsheet with the activity statuses and exclamation marks for activities with problem codes, the number of problems should be shown on the grid. If problem codes and activities are selected in the Daily Site Problem Sources Report, then a note should appear at the beginning of the report listing the problem codes and activities chosen. In the Daily Site Data spreadsheet, add the feature of marking (e.g. with the letter "R" -remark) the activities that have the comment in the activity status window. It was shown that the 24-character field for problem descriptions is often not long enough to define the problem properly. Hence, it should be longer. 128 Disable the ability to enter the following activity status given previous states as follows: • Status F prior to the statuses S, O, I, or P • Status / prior to the status S • Status S, O, I, or P after the status F • Status P after the status S, O, F, or / • Status S after the statuses O, F, or / • Status P prior to as planned status s. • More then one S or F statuses for each activity during its as-planned duration. In the Daily Site Problem Source Report, add an option of making a list of the problem codes in order of the time lost associated with them. Thus, the problem code with the longest time lost will be the first on the list. Other useful enhancements might involve: The possibility of editing photo, audio and video essays which track the construction progress; Further development of the Windows based interface which would lessen the resistance of construction personnel to acquiring new computer skills. Generating of export capabilities to Microsoft Excel, Quattro Pro, Power Point, MathLab, MathCad, and similar software for the purpose of different data presentation, utilisation and analysis (statistical analysis, construction performance modelling, claim support basis, etc) Make the system compatible with different operating environments (e.g. Windows 95, 2000, NT) 129 Chapter 5 Case Study Activity Data Findings in terms of methods, statements, productivity measurements and problems encountered were described in a number of graduate student CIVIL 598 reports (Antolis, H. and Trisno, R., 1999; Garcia, C. (a) and (b), 1999; Gharachamani, H. and Ghorbani, H. 1999) which were submitted as a part of pursuing their master degrees at the Department of Civil Engineering of the University of British Columbia. As part of my thesis research, I oversaw all of the data collection effort, captioned the relevant data for the daily site reporting, and coordinated the interaction of the students with contractor staff. I also participated with Mr. Keith Lam, a summer student in compiling in tabular and graphical form data related to productivity and production rates. Presented in this chapter is a summary of quantity takeoff, production rate, and productivity data, measurement approaches, problems encountered, and short photo essays of excavation, shoring, and concrete construction activities. The purpose of presenting this information is to provide other researchers with data sets that can be used in developing productivity. These data, in conjunction with the information presented in the previous chapter and related appendices, should provide researchers with the ability to test the validity of some of the relationships identified in the literature search presented in Chapter 2. Gathered information can be analysed to determine the causes of schedule delays, to assess the impact of weather and site conditions on activity progress, to assess the impact of encountered problems, to measure and understand productivity values under different circumstances. 130 5.1 Excavation Quantity takeoff data for bulk excavation are summarized in Table 5.1.1. Type ol Work Location Quantity Amount Unit Excavation PI 13291.8 3 m P2 17935.9 m P3 17628.2 m 3 Table 5.1.1 Quantity Takeoffs for Excavation The cycle times of the excavator CAT 3 3 OB (the hydraulic excavator was most often on the project) were analysed by the activity sampling technique. A video camera was used to record 12 hours of operation of the excavator to capture the factors affecting the production rate and the productivity of the excavator. Data related to the number of trucks for daily hauling were obtained directly either from the excavation subcontractor's flag person or its supervisor. Shown in Figure 5.1.1 is an example of the data summary sheet used in the actual production rate and productivity calculations. For purpose of comparison of values for the standard production rate of the excavator CAT 330B, data were obtained from the following sources: • Caterpillar's production rate (bank measure) = 211.17 mVhr. • RS Means Heavy Construction Data = 120.00 m3/hr. • Construction Estimating Reference Data / Craftsman Book Company = 58.81 m3/hr. • UBC Schedule = 119.84 m3/hr. • General Contractor's Schedule = 100.19 m3/hr. 131 The average cycle time on a specific observation day was as follows: • June 25, 1999 27 seconds. • July 16, 1999 21 seconds. • July 21, 1999 25 seconds. • August 10, 1999 21 seconds. • August 17, 1999 26 seconds. • August 20, 1999 24 seconds. The average cycle time of the six observations was 24 seconds, which was about 11% longer than that proposed in the Caterpillar Manual. One might conclude that the excavator operator was within the limits of expected efficiency. However, because the operator used the time the excavator had to wait for trucks to loosen materials, the obtained average cycle time was somehow misleading and the real average cycle time would probably be considerably higher. Figure 5.1.2 provides a plot of excavator cycle times for one set of observations of a 330-B CAT hydraulic excavator when carrying out bulk excavation in sandy soil. Considerable variability in the cycle times exists, and the 'standard' cycle time provided by the manufacturer is optimistic in comparison to what was observed. The actual production chart for the excavation work is shown in Figure 5.1.3. Three things are important to note with respect to this figure: (1) some of the variability arises because of the coordination of excavation work with the need for fill on another job; (2) the excavator was a shared resource, and was used for soil trimming for the shotcrete shoring system as well as for bulk excavation; and (3) the actual rates attained did not correspond either to 'standard' rates found in the literature nor to the target set by the contractor for the job. As a general observation, it was not always clear as to the scope of work treated in published standards, and 132 hence it was often not possible to make comparisons between data collected and values found in the literature. In terms of the excavation activity itself, the physical conditions encountered, Figures 5.1.4, 5.1.5, and 5.1.6 show respectively: the excavation activity; encountered poor ground conditions (hard clay) and underground water problems, and a sump pump which was installed to collect excessive ground water. 133 EXCAVATOR PERFORMANCE SHEET Sheet No. 1 of 2 DATE: June-25-99 Project: Kerrisdale Station Location: 42th Ave. & West Contractor: MATCON Boulevard Excavating and Shi ring LTD. Operation: Bulk Excavation Site Conditions: Weather: Rainy Location: West Side Fair, no congestion Temperature: 12-16 deg. Cel. Crew: 01 Excavator Equipment: Excavator 330-B Cat Type of material Excavated: Sand-Brown Operator Swing Angle: 180 degrees aprox. Elevation: 238.06 Feet aprox. Description Of Job Method: Using an Excavator type CAT-330B trucks with capacity of 8.58 m3 (BANK MEASURE), were loaded. Description of Steps included on Operation Observed: 1. - Load Bucket 6.- New Truck gets in to position to be loaded. 2. -Swing Loaded 7.- New Cycle Begins 3. -Dump Bucket 4. - Swing Empty(return) 5. - Truck Loaded Leaves Time Operation Started: Excavation begins every day at 7:30 am Time Operation Finished: The excavation operation ended every day at 3:30 pm Total Time Observed: 2hrs Cycle Average Time: 27.01 sees Standard Deviation: 6.38 Total Time that the Excavator had to wait for trucks: 2944 sees Total Time that the Excavator had to wait for trucks getting in position for loading: 178 sees Total Effective Time: 4078 sees % of Effective Time: 57% Standard Time and Standard Output: In 8 hours of operation a total of 790.79 m3 (BANK MEASURE) were hauled. Figure 5.1.1 Excavator Performance Sheet for 25-June-1999 134 Figure 5.1.4 Excavation (CAT 330B and Tandem Dump Truck) Figure 5.1.5 Poor Ground Conditions (Hard Clay) and Ground Water During Excavation \Z1 Figure 5.1.6 Sump Pump to Remove Excessive Water Main problems encountered during excavation activity were: Poor ground conditions (see Figure 5.1.5) - Excessive underground water (see Figure 5.1.6) - Inadequate internal access - Congestion Other problems that resulted in less time lost were: Too much precipitation - Wind too high (When cranes were shut down because of strong wind, everyone working at a site at that time stopped working because of safety issues. If accident happened, crane should have pulled an injured worker out of the site hole) Temperature too high 138 - Low skill level - Insufficient equipment The biggest difficulty for the research team in monitoring the excavation activity was that the work was done out of sequence, with the main reason being that the excavation subtrade was coordinating work on this site with another one in downtown Vancouver that was using fill from the Kerrisdale Project. 5.2 Shoring A shotcrete shoring system was adopted for the project. Relevant quantities in terms of anchors, soil trimming and shotcrete are summarized in Table 5.2.1. A stopwatch was used to collect cycle times of the activities involved in shoring. Photographs were also taken to help in the visualisation of the steps involved in each activity, the problems encountered, and the progress of the project. Days for sampling were chosen randomly, regardless of the day of the week, the time of the day, weather, the number of working labourers and other factors that might affect shoring production rate and productivity. Data were collected for two hours on each sampling day. A minimum of 25 observation was collected for each activity within the two-month observation period, which was started on June 23, 1999 and ended on August 27, 1999. Figures 5.2.1 (a), (b), (c), (d), (e), and (f) depict a simplified photo essay of the steps involved in constructing a shotcrete shoring system. 139 Figure 5.2.1 (b) Drilling for Anchor \k0 Figure 5.2.1 (c) Panel Reinforcement Figure 5.2.1 (d) Shotcreting Type of Work Location Quantity Quantity Amount Unit Amount Unit Anchor Installation West PI 129 Number 1100.9 m WestP2 137 Number 1157.9 m WestP3 161 Number 1226.8 m East PI 142 Number 1166.8 m East P2 163 Number 1306.1 m EastP3 95 Number 723.9 m Total m Number m Trimmed Soil (Bank Measure) West PI 459.3 3 m . . . . . . WestP2 643.8 3 m . . . . . . WestP3 855.2 3 m . . . . . . East PI 396.9 m3 . . . — EastP2 762.2 m3 . . . . . . EastP3 607.9 3 m . . . . . . Total f«* +»+( "T+1-K Trimmed Soil (Loose Measure) West PI 624.6 m3 . . . . . . West P2 875.5 m3 . . . . . . WestP3 1163.0 m3 . . . . . . East PI 539.8 m3 . . . . . . EastP2 1036.6 m3 — . . . EastP3 826.7 m3 . . . . . . Trtal nS Shotcrete Wall West PI 752.3 m2 58.0 m3 WestP2 463.7 m2 47.1 m3 West P3 437.8 2 m 44.5 m3 East PI 788.4 m2 58.1 m3 EastP2 526.7 m2 53.5 3 m EastP3 324.2 m 32.9 m3 Total 2Mt y Note: The 752.3 m2 area included 289.5 m 2 with a thickness of 0.04 m and 462.8 m 2 with a thickness of 0.10 m. The 788.4 m2 area included 346.0 m2 with a thickness of 0.04 m and 442.4 m 2 with a thickness of 0.10 m. Table 5.2.1 Shoring Quantity Takeoff Data 5.2.1 Anchor Installation Data on DYWTDAG and JJBO soil anchor installation were collected by timing tasks using a stopwatch. Tables 5.2.2 and 5.2.3 present data collected and the actual production rate and productivity of the installation of the two types of soil anchors used. The average production rate of DYWIDAG soil anchor installation was 48.1 meters depth of drilling per hour and that of JJBO soil anchor installation was 42.7 meters depth of drilling per hour. 144 c > — ^ o 2 CD O-S c — 2 2 o 3 3 D ro I 2 o a. o Ol 7 o O g S « oa = TJ a " a S c o a. < oi c O i o in Z o TJ Ol co a III m o " C 0) S — <o < 2 to c N o = CO 1 = £ a t: o o> «- .c c o o a> c -J < ,_ c P • m 2 3 s UJ o 2 E z c o C L E o O o z Table 5.2.2 Production Rates and Productivities of EBO Soil Anchors Installation in the Kerrisdale Station Project' 145 111 M l a e o a. < •- = O « o £ M l * — o o 2 o 11 = < X " • • 3 Q (C OT Qj | 1 5 S. ! £ § £ s o = e = = (O "C 5 TJ O S s s g 3 _ U z o = £ E S i 5 o ™ o O) C O C OJ £ 3 .2 o O Ul — ™ W — " « TT fl I Si I o v c .c a. a) « ° E I S 8 w 3 -S g I f - & » 5 c c a . « « E ° E £ o. o S T ) • -B £ £ M J2 C ™ £ §2 I ~ c £ v g i g>£ 0 £ » g £ °»— E g £ a a a E o H « o a» £• S t £ S .S S * i « -2 ° S I 11 1 f s s ID i - O i £ .s = i s « a S Q . •> 1 2 E ca r- a. o J2 f c >- _ 3 =5 3 3 O o o ? : Table 5.2.3 Production Rates and Productivities of DYWTDAG Soil Anchor Installation 146 5.2.2 Soil Trimming Before wire meshes were installed, the soil had to be trimmed. The excavator used for soil trimming was CAT 320L that used a bucket with teeth and a capacity of 0.76 m3. Tables 5.2.4 (a) and (b) present the data collected with the collected data on soil (sand and wet clay) trimming and their analyses. In most observations, the type of soil trimmed was loose to compact sand. Wet clay with groundwater was only observed on August 19, 1999. The excavator CAT 320L was used in soil trimming most of the time. The excavator CAT 330BL was only used in soil trimming on August 19, 1999 when the excavator CAT 320L was returned. The duration of soil trimming was the time needed to trim the soil slope at one panel by the excavator. At each panel, the excavator trimmed the soil, loaded the materials to its 1-yd3 or 0.76-m3 bucket, swung loaded for about 90°, dumped the trimmed soil, swung unloaded and trimmed the soil again until the soil slope was finished. Two data analyses based on the types of soil trimmed were performed to investigate the effect of soil types on soil trimming production rate and productivity. Unfortunately, only seven data sets were collected for wet clay conditions because most of the clay had been trimmed before observation of this activity was started The average production rate and productivity of soil trimming in clay with groundwater conditions present were higher than those in sand conditions. This difference might be attributed to the use of the excavator with a higher capacity (CAT 330BL) in wet clay trimming. 147 Observation Number Weather Type of Soil Crew Number Number of Men in One Volume of Soil Duration Production Rate Productivity Crew" (V) (Minutes (Hour) {m3/hr) (m3/m-hr) 1 1 2 3.4 4.5 0.1 45.9 22.9 2 1 2 4.2 5.1 0.1 49.1 24.5 3 1 2 5.1 10.3 0.2 30.0 15.0 4 1 2 4.2 5.9 0.1 43.3 21.6 S Clear Sand 1 2 1.9 5.1 0.1 22.8 11.4 6 1 2 5.9 11.5 0.2 30.9 15.4 7 1 2 4.4 7.5 0.1 35.1 17.5 8 1 2 4.4 13.9 0.2 19.2 9.6 9 1 2 4.1 10.8 0.2 22.6 11.3 10 1 2 5.0 6.9 0.1 43.4 21.7 11 1 2 5.3 8.4 0.1 38.0 19.0 12 1 2 5.2 10.2 0.2 30.6 15.3 13 Cloudy Sand 1 2 6.5 10.9 0.2 36.2 18.1 14 1 2 5.0 10.8 0.2 27.6 13.8 15 1 2 5.6 13.3 0.2 25.5 12.8 16 1 2 8.9 11.9 0.2 45.1 22.6 17 1 2 4.4 4.6 0.1 57.9 28.9 18 1 2 4.0 5.5 0.1 43.5 21.8 19 1 2 5.3 7.4 0.1 42.7 21.3 20 1 2 3.0 5.3 0.1 34.3 17.1 21 1 2 4.9 10.3 0.2 28.5 14.3 22 1 2 3.5 5.5 0.1 38.2 19.1 23 1 2 5.1 7.1 0.1 43.3 21.6 24 Cloudy Sand 1 2 3.8 4.9 0.1 45.7 22.9 25 1 2 2.3 6.6 0.1 20.8 10.4 26 1 2 5.9 5.6 0.1 63.3 31.6 27 1 2 4.6 7.9 0.1 35.1 17.5 28 1 2 5.1 5.7 0.1 53.8 26.9 29 1 2 4.7 5.2 0.1 54.2 27.1 30 1 2 4.8 5.5 0.1 51.6 25.8 31 1 2 5.0 5.8 0.1 51.6 . 25.8 Note: One crew consisted of one operator for CAT-320L, one labourer, and hydraulic excavator CAT-320L with 0.76 m3 bucket capacity Table 5.2.4 (a) Production Rates and Productivity of Sand Trimming Observation Number Weather Type of Soil Crew Number Number of Men in One Crew* Volume of Soil Duration Production Rate Productivity (mJ) (Minutes] (Hour) (m3/hr) (m3/m-hr) 1 Cloudy Clay + Ground Water 1 2 4.6 5.2 0.1 53.1 26.5 2 1 2 8.1 7.4 0.1 65.8 32.9 3 1 2 6.3 3.4 0.1 111.7 55.9 4 1 2 3.6 5.2 0.1 41.2 20.6 5 1 2 3.3 3.0 0.0 66.6 33.3 6 1 2 4.5 4.1 0.1 65.4 32.7 7 1 2 2.8 3.9 0.1 42.0 21.0 Note: One crew consisted of one operator for CAT-330BL, one labourer, and hydraulic excavator CAT-330BL with 0.76 m3 bucket capacity Table 5.2.4 (b) Production Rates and Productivity of Wet Clay Trimming 148 5.2.3 Soil Removal Soil trimmed for the shoring system was removed using an excavator CAT 320L with 3 * • 3 bucket capacity of 1.10 m and trucks with trailers with a total capacity of 11 m . Only a few data samples related to soil removal were collected (see Table 5.2.5) because most of the trimmed soil was moved to the place of bulk excavation. If more workspace was required, the excavator CAT 320L or CAT 330BL moved the trimmed soil directly to a dump truck. In most observations, the type of soil trimmed was sand. Two types of buckets were used. The excavator CAT 320L used a 1.10-m3 bucket while the excavator CAT 330BL used a 2.83-m3 bucket. A cycle in soil removal included loading the bucket, swinging loaded, dumping the soil and swinging unloaded. The cycle time is calculated by dividing the time needed to load a truck or trailer truck by the number of cycles performed. Two data analyses based on the type of excavator used were performed on soil removal. 149 Productivity (m'/m-hr) 1 1 83.7 1 75.7 148.5 98.2 124.4 172.2 101.5 169.7 I 76.2 | I 268.1 I 155.1 109.9 I 308.7 | I 246.5 I 218.3 178.7 355.4 193.4 I 293.9 | Production Rate E 1 167.3 I I 151.3 I I 297.0 I | 196.4 I I 248.8 | I 344.3 I I 203.1 I I 339.4 I | 152.3 | I 536.2 I I 310.3 I I- 219.9 I | 617.5 | | 493.0 I I 436.6 I I 357.5 I I 710.8 I | 386.9 | | 587.8 | Cycle Time (Hour) | 0.01 | I 0-01 I I 0.00 I I 0.01 I I 0.00 | | 0.00 I 0-01 I | 0.00 I 0.01 | I 0.01 I 0.01 I I 0.01 | | 0.00 | | 0.01 | I 0.01 | I 0.01 | | 0.00 | I 0.01 | | 0.00 | Number of Cycles CO CN t— CO CO CN CO CO CO CO CO CO CO CO co CO CO CO CO co Time to Load a Truck / Trailer (Minutes) •* CM CO CN CO o CN CO . — CN cn CN T — co CM o> 1— CO co' CO r-; CM' CO CN O) CM T CO CM r--Number of Men per Crew <N CN CN CN CN CN CM CN CN CN CN CM CN CN CN CN CM CN CN Crew Number Excavator Type i CAT 320L | | CAT 320L | | CAT 320L | | CAT 320L | | CAT 320L | | CAT 320L j | CAT 320L j | CAT 320L | | CAT 320L ] CAT 330BL | CAT 330BL | I CAT 330BL | | CAT 330BL | | CAT 330BL j | CAT 330BL | | CAT 330BL \ | CAT 330BL | | CAT 330BL | LCAT 330BL j Bucket Capacity rt E oo CN oo CN oo CM oo CN co CM oo CM* oo CM CO CN co CM oo CN Type of Soil band Sand Sand Weather Clear a c C i T C C •* 1 1 ) Observation Number T" CN CO -9 IO co 00 cn o •r- CM CO CO f- CO cn Table 5.2.5 Production Rates and Productivities of Soil Removal 5.2.4 Panel Reinforcement Table 5.2.6 summarizes the data collected on the installation of panel reinforcement. The number of trade persons in the panel reinforcement crew varied every day, and each trade person installed one panel. The soil type was loose to compact sand in most observations. Data associated with clay and groundwater were collected on August 19, 1999. Two data analyses based on the types of soil were performed to investigate the effect of soil types on panel reinforcement production rate and productivity. Because the number of labourers working on one panel was one, the value of the production rate was always equal to that of the productivity. 151 Productivity i E E 15.8 OO O oo CS 00 —TTi 12.0 o co' I 23.7 co 00 —153 Ol Ol Til 10.4 CO cri cvi IO CO •o CO 00 O CM CO CO CO IO to 10.2 CM IO Ol CO CD* CO CN CO* © Production r " C .e ft" E 03 to' to co o oo' CM CO o CN o cd c-co' CN CO 00* •*»• CO CO ai 00 d CO oi CM IO CO IO CO 00 o •* CN CO CO ai m to' CN d CM IO CO •«* CO CO* CO* CN CO itlon V—" 3 O I CO d - in d CO d to d d p CN d CO d d d CO d d IO d cn d 00 d 00 d CO d 00 d p CN d d - i l -ea IO d d CN d m d CM d c 3 Q "ST 4) *5 c 2 CM CO T-o w' CO <o ai CM f~ CO CO cn CO CM cri CO o cri in CO co' •* co' CO IO CN CN GO CO CN d CN CN •«* CM cn cd CN • * CM' to co OO •>*• CO r»* TJ-to oo' <q CO CO -<r CO CN o CM' CM CO r-° CN CO CM o CO CO* CN CN f f sa of One Panel E. CO o Oi co o to" cn io' at r~" cn io' •<f ui cq O ui O «r o •* CN CO X — csi cn CM CO co" r— ci eo" CO co' CO CM o CN 00 co' CM" CO to CO CM in c < Number of Men Type of Soil n c CO CO 73 c CO CO + 1 CD C o 5 1_ CD I Weather w co 03 O >. •a 3 O L) > n 3 c O « Observation Number T- CN co IO IO 00 cn o r— r -« -N CO r -IO to *-co CO o CM CM CM CN co CM rt CM IO CM co CN r-CM co CM Table 5.2.6 Production Rates and Productivities of Shoring Panel Reinforcement 5.2.5 Shotcreting Table 5.2.7 summarizes the data collected on shotcreting. The duration of shotcreting was the time needed to shotcrete one panel. The volume of shotcrete sprayed on one panel was calculated by multiplying the area of one panel with the shotcrete thickness, which was 4 inches or 0.10 meter. All of the data collected was for panels over sand walls. 153 Productivity (Area) c E r-oc CC •A CN oc CO c i 1 -c t» oa CO c oa c a c CN CN c\ It CN c c: •»-•fl w T" cc u CO m CM « f -r» O Ol CN CN CN CN •fl Cs a CN W co Cs CO c <N CN C CN w oc 1-• f l a cs in cc T-Ui Ul 18.6 Productivity (Volumetric) i E E o> V) .— co •* fl| CO •fl; CO co .— CM o i in CS CO CO CD CO o i •>«• CO o i CO o i m o i m oi -^o i •fl-o i o i O CM o> o i o> CO 1— o> Production Rate (m*/hr) 03 r-' ui I f r-" in ui CD in" co CO ui co r-" CO o cn o i co in CO co' CO CO* 10.4 -r ui CM cri o cri co oi o> ai in co' m o> •* 00* CM CO* m co 00* m r-~" co co' CO I - " ition (Hour) d o" d d d d d d d d d o d o d d O l d d o o o d o d o d CM d d o d d o d d o d d .— d Dun (Minutes) co ui "9-r~* o co' o> o> CO CM •fl* o co O •fl-oo •fl-" r-" cn o i CO oi co' 12.5 oo CO CN o i co o i CM o i o i 12.1 CN co' •fl-o i CO CO* CD oi m co" CO oi c i CO Volume of Shotcrete at One Panel n E, d t -o" r--d r » d •fl-d d •* d U l d w d d co CO d CM d CD d CN o i CO d CO d d •«(; d •fl-d .— m d CO d m d CO d m d CO d co d oo d Area of One Panel « E CM r-' CM f-* CN r-~" CN i - " CO co CO CO CO co 00 OS o r--' 12.4 m o i o i CO CD 21.2 •* CO co m CO CO co' •fl-•fl- 16.9 m' CM co" in* CM co* oo •fl-O) o i CM CO CO Number of Men In a Crew •fl- •<t •fl- •fl- •fl- •fl- •fl- •fl- fl- •fl- •fl- ->r fl- •fl- fl- • f l- fl- • f l- •fl- •fl- fl- •fl- •fl- •fl- • f l A- •fl-Crew Number 1 Weather c; CO Clear Clear Observ. Number CM co •<t m CO oo on o CM co t - fl- m co ea cn ea CM CM CM CM CO CM fl> CM CM CO CM CM CO CM o> CM Table 5.2.7 Production Rates and Productivities of Shotcreting 154 5.2.6 Anchor Tensioning The last step in the shoring activity was anchor tensioning, which was done by applying a proof load test followed by a lock-off load to the anchors. Table 5.2.8 summarizes the data collected on anchor tensioning. Two labourers were assigned to perform the tensioning activity. One of them handled the hydraulic pump and the other installed other equipment. Only two problems associated with anchor tensioning were observed, which were re-tensioning and the difficulties in removing nuts from bolt extensions. No significant factors seemed to have any major effect on the production rate and the productivity of the anchor tensioning activity because it involved simple procedures, small working space and few workers. 155 o 3 •a o « c > o a o <g 3 3 S E o £ 3 i. U Q. c o o S 3 « 1 - c I g 5 ° o 5 3 Q O I— 2 * f] c e • I s > « > xi £ E O 3 z * o" Q. O >» 5 i— < « c o > <B » E S 3 O Z CN CN CN 5 cn 00) co" 00 IO 00 CD* CO iri CO CN <P CN CO 00 00 S2 l° l cn in 5 CN CN CN CN 3 Q O m CO _cu O co 4J 3 cn ^ cn o s CM >» 3 CO ^ cn CM CM o o > vt s= </> 2 C 3 0 E 1 o CD w to CU ° E 2 2 CO c x> o II CO co vt o -§ o E a. 3 Vt ca 3 2 2 o 0 u CD CL « vt -a • i =3 c cr _ 3 ro CD O 1 «• — <0 JS ro o •-3 TJ CD > E 3 o > "ro 3 E 3 O « O Z Table 5.2.8 Cycle Time Record, Production Rates and Productivities of Anchor Tensioning 156 Major problems encountered during shotcreting activities were: - Poor ground conditions - Excessive ground water - Tool/equipment breakdown - Poor trade coordination. Minor problems encountered were: Too much precipitation Congestion - Rework due to quality problems. 5.3 Concrete Construction The following sections present the data collected on concrete construction and their analyses in the following order: crane usage, footings, columns, walls, suspended slabs and slabs on grade. Sample calculations of the actual and standard production rate and productivity for each concrete element are also described. 5.3.1 Crane Usage Raw data on crane usage in the construction of footings, columns and walls are summarised in Table 5.3.1. Direct observation, the use of stopwatch, and photo recording techniques were used for activity sampling. 157 1 c o a CO _o cs TJ «i I «i •XL 4» £ c o •s E *. M c o o *5 5 c E _3 O u oi c u. JC a oi (9 <n Z3 o c E o fc. o jt o »-TJ c CO a LU O a E E 3 CO o '1 i5 < I I: E LU Ol w •a 1 ? I ? I 11 2 E o a Ol c CL •c MW CO o c o o o u. 2 cc 3 o o % o cs a .SI c o 2 LU o co co - -CD C» £J J-co to co co •«• co 5? s S 2 r~ o o N « O) ro O CO - o co CM 55 CM CM — „ o o •«r co • m o " *" ^ o o ^ o >- o 2 CM CO S J S S | (S 5 — — cn co B « « n o o S 5 3 O a. 2 o E 41 TJ 0) TJ U C O O 4> E xi o o O c o c o •s Cu * J •a 5 $ f 4) O TJ <-> 2 + § . 2 .g- + § (0 •8 o (A « § » * O <D < CJ It o "5 o £ o z £ CL C o 3 CO "5 TJ (A "E 41 £ c c o •G 5 *. M C o u TJ C a c E _3 O o a cn a M 3 41 Ol 3 4) a. a> c s a 4) o TJ C CS ** M a LU 0 £• a E E 3 <0 fc E LU Ol _c Ol CO TJ a c O l * g o S £ 11 E E o o oi c *a. a. 2 o c o o o cs .a at CC 3 o CS a 5 c o 2 CM CO O CM 121 O d s cn CM cn cn 8 41 C (0 w o •£ 4) s cn vo •M- CO iri co o o *». ° CM m -a-co CM CM in in CM CM cvi co r~ ro < 4) 4, Ol o) £ CO 4> flj Table 5.3.1 Summary of Crane Usage 158 5.3.2 Footing Construction Quantities, production rates and productivities of footing formwork, concrete placement and stripping are shown in Table 5.3.2. Data on the construction of footings were collected by stopwatch to measure its production rate, productivity and labour utilisation factors. Figures 5.3.1 (a), (b), (c), (d), (e), (f) and (g) show a photo essay of the steps involved in constructing a concrete column footing. A simplified photo essay of exterior strip footing construction is depicted in Figures 5.3.2 (a), (b), (c), and (d). Figures 5.3.2 (a) through (d) show the construction of a perimeter strip footing which supports the perimeter wall of the substructure. One of the problems encountered (excessive ground water) is shown in Figure 5.3.3. 159 co 2 c o « z o. >. K C" tu o o CL E o u E o. — 3! fi o E > o> t C £ 8 ° E o z o 5 o o .c .c f .c E E E E E E E E n o T « € € € CM W E E E a •o E to n <o i S co £ ~ .c .c .c .c E E E E <r> r> m E E E E IO CN CO D £ £ € £ i <n <i <n E E E E to TJ <5 « 55 £ CL E TJ" o o E E E E SI CM «M CfXl E E E E r— o co CD € € € € M CM tx rx E E E E CO CO CN * ~ ai csi o •2 I E « c 2 ca £ x — cu S ca £ co 2 £ 3 -•a E o 1 Q. t= O o JO ro O 10 TJ (O fi I «fl CO co -3 T *- m a -if 9 § E * O O Table 5.3.2 Quantities, Production Rates and Productivities of Footing Formwork, Concrete Placement and Stripping 160 161 Figure 5.3.1 (c) Installing Footing Formwork Figure 5.3.1 (d) Footing Reinforcement 162 Figure 5.3.1 (e) Placing Footing Concrete Figure 5.3.1 (g) Footing Concrete Finishin Figure 5.3.2 (a) Installing Strip Footing for Perimeter Walls Figure 5.3.3 Excessive Ground Water in Hole Excavated for Footing 5.3.3 Column Construction Data on quantities, production rates and productivities of column formwork, concrete placement, and stripping are given in Table 5.3.3. Data on the construction of columns were collected by stopwatch to measure its production rate, productivity and labour utilisation factors. Figures 5.3.4 (a), (b), (c), (d), and (e) provide simplified photo essay of the steps involved in constructing a concrete column. 167 ™ 2 Q. >, E Q. -~ •= C 2 i-1 E E .E E E E E E E E E Q n ct « « S, ~ in S E E O Ol E E E E i n n « E E E E <r> co <D N (O (*) *ri oj cri ci i — « n *» E E E E n t | o *r °1 i o j •e I E <• E 2 « E x ~ o « « — S «o £ S E E E E E E 1 0 %- *-£ 5 £ e € e € K «>« CV — E E E 6 g § S s » s Q •g E c | 1 E| co « ci E c o S E , o o Table 5.3.3 Quantities, Production Rates and Productivities of Column Formwork, Concrete Placement, and Stripping 168 Figure 5.3.4 (a) Column Forms Arrive on Site Figure 5.3.4 (b) Installing Column Reinforcement Cage Figure 5.3.4 (c) Installing Column Form Figure 5.3.4 (e) Finished and Stripped Columns 5.3.4 Wall Construction Data collected on quantities, production rates and productivities of wall formwork, concrete placement and stripping are given in Table 5.3.4. Again, data on the construction of walls were collected by stopwatch Figures 5.3.5 (a), (b), (c), and (d), provide a simplified photo essay of the steps involved in constructing a concrete wall. Figure 5.3.6 shows rework that had to be done because of formwork failure. 171 ™ z CL ^ o O 1 I C A S E £ •5 E E E E S| (M (N (M E E E e (D o ^ a s ot iri o to co £ „ « £ £ E E E E »— CO S r «?, ' CO CM a I i c | J a> 2 ro — 2 w 2 S CO O j co'. try o» OJ cn £ £ c r E E E E E *£ "E *E D co to o p p p csi d o ^ € € € € 1 o n r> E E E £ o 2 o> w rt " t7> CD CO ^ CO II E E E "E E E E E E *E T= *E o ( n m < rt Jg co p •fl .n' N 0> CM rt — £ £ £ # E E E E to cb to OJ 2 CD " CN S e I I • * -if o co £ 2 o 2 2 a Q c = o t u o o S § U o B " o £ • ° «• z •> =. * S "3 "D « m in jt o g o o) ~ S * .§ g "E S S H • 3 3 C i re 2 E o> o a) a) £ m £ § > m Table 5.3.4 Quantities, Production Rates and Productivities of Wall Formwork, Concrete Placement and Stripping 172 Figure 5.3.5 (c) Installing Wall Reinforcing Figure 5.3.6 Rework Required due to Formwork Failure Major problems encountered during footing, walls and columns construction were: - Wind too high which affected use of crane - Too much precipitation Congestion. Minor problems that occurred during concrete subconstruction activities were: Waiting for Drawings - Rework due to quality problems, including formwork failure. 5.3.5 Slab on Grade Data collected on quantities, production rates and productivities for slab-on-grade concrete placement are given in Table 5.3.5. Data on the construction of slabs-on-grade were collected by video recording and stopwatch. Figures 5.3.7 (a), (b), (c), and (d), provide a summary overview of the steps involved in constructing a slab on grade. 176 Productivity Unit JZ I E CO E JZ £ E JZ | CO E JZ E CO E JZ 1 E to"* E JZ • E co"*" E SZ JZ SZ JZ I I I I E E E E CO CO CO CO E E E E Means 1.55 m3 /m-hr General Concrete 3.08 - 3.29 m3 /m-hr Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I JZ f E CO E JZ i E CO E JZ I E CO E JZ 1 .E CO E x: JZ JZ jz I I I I E E E E CO CO CO CO E E E E Means 1.43 m3 /m-hr General Concrete 1.47-1.56 m3 /m-hr Productivity Amount 5.38 2.48 4.20 3.24 3.19 3.15 3.61 1.03 5.38 t AO Z.48 Means 1.55 m3 /m-hr General Concrete 3.08 - 3.29 m3 /m-hr Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I 2.23 2.08 1.86 2.64 Mean 15.39 m3 /hr 2.20 Standard Deviation 2.62 m3 /hr 0.33 Maximum 18.48 m3/hr 2.64 Minimum 13.03 m3 /hr 1.86 Means 1.43 m3 /m-hr General Concrete 1.47-1.56 m3 /m-hr Production Rate Unit •5 CO E E CO E CO E E CO E € £ =5 € CO CO «o to E E E E Means 1.55 m3 /m-hr General Concrete 3.08 - 3.29 m3 /m-hr Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I rt^ E rt^ E CO E <£ CO E Mean 15.39 m3 /hr 2.20 Standard Deviation 2.62 m3 /hr 0.33 Maximum 18.48 m3/hr 2.64 Minimum 13.03 m3 /hr 1.86 Means 1.43 m3 /m-hr General Concrete 1.47-1.56 m3 /m-hr Production Rate Amount Concrete Pump and Vibrator 48.40 24.82 37.78 19.42 19.16 25.23 Mean 29.13 Standard Deviation 11.61 Maximum 48.40 Minimum 19.16 Means 1.55 m3 /m-hr General Concrete 3.08 - 3.29 m3 /m-hr Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I 13.41 16.64 13.03 18.48 Mean 15.39 m3 /hr 2.20 Standard Deviation 2.62 m3 /hr 0.33 Maximum 18.48 m3/hr 2.64 Minimum 13.03 m3 /hr 1.86 Means 1.43 m3 /m-hr General Concrete 1.47-1.56 m3 /m-hr Time (Hours) Concrete Pump and Vibrator 4.00 4.50 3.00 4.25 AM 3.75 Mean 29.13 Standard Deviation 11.61 Maximum 48.40 Minimum 19.16 Means 1.55 m3 /m-hr General Concrete 3.08 - 3.29 m3 /m-hr Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I 5.00 3.11 2.55 3.30 Mean 15.39 m3 /hr 2.20 Standard Deviation 2.62 m3 /hr 0.33 Maximum 18.48 m3/hr 2.64 Minimum 13.03 m3 /hr 1.86 Means 1.43 m3 /m-hr General Concrete 1.47-1.56 m3 /m-hr Crew Composition Equipm ent Concrete Pump and Vibrator Mean 29.13 Standard Deviation 11.61 Maximum 48.40 Minimum 19.16 Means 1.55 m3 /m-hr General Concrete 3.08 - 3.29 m3 /m-hr Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I T— Mean 15.39 m3 /hr 2.20 Standard Deviation 2.62 m3 /hr 0.33 Maximum 18.48 m3/hr 2.64 Minimum 13.03 m3 /hr 1.86 Means 1.43 m3 /m-hr General Concrete 1.47-1.56 m3 /m-hr Crew Composition Labour Used: Redi-Mix Concrete Delivery, OJ o o> CO CO co Mean 29.13 Standard Deviation 11.61 Maximum 48.40 Minimum 19.16 Means 1.55 m3 /m-hr General Concrete 3.08 - 3.29 m3 /m-hr Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I CO co Mean 15.39 m3 /hr 2.20 Standard Deviation 2.62 m3 /hr 0.33 Maximum 18.48 m3/hr 2.64 Minimum 13.03 m3 /hr 1.86 Means 1.43 m3 /m-hr General Concrete 1.47-1.56 m3 /m-hr Crew Size Used: Redi-Mix Concrete Delivery, CJ) o cn CO co CO Mean 29.13 Standard Deviation 11.61 Maximum 48.40 Minimum 19.16 Means 1.55 m3 /m-hr General Concrete 3.08 - 3.29 m3 /m-hr Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I CO CO Mean 15.39 m3 /hr 2.20 Standard Deviation 2.62 m3 /hr 0.33 Maximum 18.48 m3/hr 2.64 Minimum 13.03 m3 /hr 1.86 Means 1.43 m3 /m-hr General Concrete 1.47-1.56 m3 /m-hr Quantity Unit Used: Redi-Mix Concrete Delivery, n E rt E E rt E « E rt E Statistics Comparison Standards Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I rt E rt E co E CO E Statistics Comparison Standards Quantity Amount Type of Equipment 193.6 111.7 113.4 82.5 84.5 94.6 Statistics Comparison Standards Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I 67.0 51.8 33.2 61.0 Statistics Comparison Standards Weather Type of Equipment Sunny Sunny Sunny Sunny Sunny Rainy Statistics Comparison Standards Type of Equipment Used: Redi-Mix Concrete Delivery and Concrete Pump I Sunny Sunny Sunny Sunny Statistics Comparison Standards Date Day o CO o CM CM CM CM CO CM Statistics Comparison Standards CM CM co Oi r--CN Statistics Comparison Standards Date Month September October October October October October Statistics Comparison Standards September October October October Statistics Comparison Standards Observa tion Number T— CM co m CO Statistics Comparison Standards CM CO Statistics Comparison Standards Type of Work Suspended - Slab Placement Concrete Placement Slab on Grade Placement Table 5.3.5 Quantities, Production Rates and Productivities for Slab on Grade and Suspended Slab Concrete Placement Figure 5.3.7 (a) Preparation for Slab on Grade (Stone Slinger Fills in Slab on Grade Foundation with Gravel) Figure 5.3.7 (b) Preparation for Slab on Grade (Compaction of Gravel Foundation) 178 Major problems encountered during slab on grade construction were: Too much precipitation and - Wind too high (When the crane was shut down, none of the workers were allowed to continue working at the site. Minor problems encountered were: Tools/Equipment breakdown - Waiting for Drawings Congestion 5.3.6 Suspended Slab Data on quantities, production rates and productivities for construction of a suspended slab are given in Table 5.3.5. Data were collected by videotaping and stopwatch. Figures 5.3.8 (a), (b), (c), (d), (e) and (f), provide an overview photo essay of the steps involved in constructing a suspended slab. Problems encountered during suspended slab construction were similar to those encountered in slab on grade construction. 180 Figure 5.3.8 (a) Receipt of Shoring Frames Figure 5.3.8 (b) Assembling Shoring 181 Figure 5.3.8 (e) Placing 4x6 Cross Support Members Chapter 6 Conclusions and Recommendations 6.1 Conclusions The intent of this thesis was to improve the understanding of productivity as a function of site condition and construction methods. The literature review determined what the state-of-the-art in predicting productivity as a function of different factors present was. No definitive, universal relationship was found, but important contributions were made in that direction. An important finding was that few data sets from actual projects existed to help researchers to develop predictive relationships. A second contribution relates to the testing and refinement of a daily site reporting system. This system allows the recording of construction activities, site condition, environment data, on-site equipment and usage, job-site visitors, inspections, meetings, problems encountered, etc. Refinements arising from the work for this thesis deal with the visualization of daily site data in terms of 2-D and 3-D representations. The ability to visualize data is important because it helps: (1) explain events on the site, (2) determine the reasons for construction delays, and (3) identify corrective actions. The daily site records and productivity records provided a comprehensive set of data to be used by other researchers in testing various theories and developing predictive relationships. A third contribution was conducting a detailed case study of the construction of the substructure of an actual project. The goals of the case study were to develop comprehensive data sets for the construction of different elements, recording the methods used, problems 184 encountered, and so forth. The thesis emphasized the difficulty of accurately monitoring a site, and highlighted the level of effort and resources involved in collecting reliable data. It helped place into perspective the likely quality of data that were collected on actual projects by site personnel who were preoccupied with advancing the work. A part of this contribution is exploring various data collection methodologies that are described in the literature and their effectiveness in the field. The following suggestions were made: Introduce the goal of the research to the construction personnel and explain the purpose of the observer's site visits; Explain the use and purpose of input data to each person asked to provides the data; Do not ask for data that are too detailed and/or difficult to provide; Show each person how his or her data are useful to the management and the company; Minimize the narrative requirements of the forms, and Never ask a person to provide a single item of information twice (by two different team members) or to supply apparently redundant information. 6.2 Recommendations The following issues were identified for further consideration: Detailed recommendations were given for enhancing the user interface of the daily site reporting system. Further work should be pursued to enhance the ability to visualize site data and superimpose various types of data to help determine cause-effect relationships. Based on the collected data, an attempt should be made to develop empirical relationships between site conditions information and productivity. 185 References Abdelhamid, T.S., and Everett, J.G., Time Series Analysis for Construction Productivity Experiments, Journal of Construction Engineering and Management, Vol. 125, No. 2, March/April 1999, pp. 87-95 Adrian, J.J., Construction Claims, Prentice Hall, New Jersey, 1988 Adrian, J.J., Construction Productivity Improvement, United States of America, 1987 Allen, R.K., The Estimation of Construction Contract Liquidated Damages, Civil Engineering Practice, Spring/Summer 1995, pp. 7-16 Anatolis, H. and Trisno, R., Study of Shoring Method on Kerrisdale Station Project, CIVIL 598 Project, University of British Columbia, Vancouver, 1999 Arditi, D., Construction Productivity Improvements, Journal of Construction Engineering and Management, Vol. I l l , No. 1, March 1985, pp. 1-14 Ashley, D. A., Uehara, K. and Robinson, B.E., Critical Decision Making During Construction, Journal of Construction Engineering and Management, Vol. 109, No. 2, June, 1983, pp. 147-162 Baki, M. A., Delay Claims Management in Construction - a Step by Step Approach, Cost Engineering; Morgantown, Oct, 1999, pp. 36-42 Bernold, L.E., Simulation of Nonsteady Construction Processes, Journal of Construction Engineering and Management, Vol. 115, No. 2, June, 1989, pp. 163-178 Boussabaine, A.H., Grew, B.R. and Currin, D., Increasing On-Site Productivity Through Wireless Computer Control, Durability of Building Materials and Components 8. (1999), Institute for Research in Construction, Ottawa, pp. 2277-2286. Bubbers, G. and Christian, J., Hypertext and Claim Analysis, Journal of Construction Engineering and Management, Vol. 118, No. 4, December 1992, pp. 716-730 Chang, L., Analytical Techniques to Improve Construction Productivity, American Association of Cost Engineers, Transactions, 1988, pp. 19-25 Chang, L. Measuring Construction Productivity, Cost Engineering, Vol 33/No.lO, October 1991, pp.H2.1-H2.8 Chao, L.C. and Skibniewski, M. J. Estimating Construction Productivity: Neural-Network-Based Approach, Journal-of-Computing-in-Civil-Engineering. v 8 n 2 Apr 1994, pp. 234-251. Chitester, D.D., A Model for Analyzing Jobsite Productivity, American Association of Cost Engineers, Transactions, 1992, pp. C3.1-C3.5 Choo, H.J., Tommelein, I.D., Ballard, G., andZabelle, T.R., WorkPlan: Database for Work Package Production Scheduling, Proceedings IGLC ' 98, Guaruja, Brazil Christian, J. and Hachey, D., Effects of Delay Times on Production Rates in Construction, Journal of Construction Engineering and Management, Vol. 121, No. 1, March 1995, pp. 20-26 Coble, R. J., Expanding Pen Computing Capabilities to Include More Effective Field Applications, Computing-in-Civil-Engineering-(New-York).v 2 1995, ASCE, New York, NY, USA. pp. 1340-1343. Construction Industry Board, CIB Recommends How to Achieve 30% Cost Reductions, News release: 1 August 1996, http://www.ciboard.org.uk/ Construction Law Letter. Assessment of Contractor's Productivity Loss Resulting From Owner's Interference, Vol.13, No.4, 1997, pp. 1-4 Dieterle, R.A. and DeStephanis, A., Use of Productivity Factors in Construction Claims American Association of Cost Engineers. Transactions of the American Association of Cost Engineers; Morgantown; 1992, pp. C. 1.1 -C1.7 Drewin, F.J., Construction Productivity, Measurement and Improvement Through Work Study; Northern Alberta Institute of Technology, Elsevier, 1982 Eldin, N.N. and Egger, S., Productivity Improvement Tool: Camcorders, Journal of Construction Engineering and Management, Vol. 116, No. 1, March, 1990, pp. 100-111 Elzarka, H.M. and Bell, L.C., Development of Pen-Based Computer Field Applications, Journal of Computing in Civil Engineering 11 n 2 Apr 1997, p 140-143. USA. pp. 327-334. Elzarka, H.M., Bell, L.C. and Floyd, R.L., Applications of Pen Based Computing in Bridge Inspection, Computing-in-Civil-Engineering-(New-York).1997, ASCE, New York, NY, USA. pp. 327-334. Fazio, P., Chutter, D., Bourassa, G., Russell, A.D., Construction Industry Factors Impairing Productivity, American Association of Cost Engineers, Transactions, 1984pp. H5.1-H5.8 Finke, M.R. Statistical Evaluations of Measured Mile Productivity Claims, Cost Engineering, Vol. 40, No 12 December 1998, pp. 28-30 Garcia, C , (a) Excavation Operation at Kerrisdale Station, Study of Factors Affecting the Performance of the Excavator Operator, CIVIL 598 Project, University of British Columbia, Vancouver, 1999 187 Garcia, C , (b) Study of Factors Affecting Productivity of the Concrete Crew During the Placement of Concrete in Six Suspended Slabs and Four Slabs on Grade at Kerrisdale Station, CIVIL 598 Project, University of British Columbia, Vancouver, 1999 Gharachamani, H. and Ghorbani, H., Monitoring Field Productivity on the Kerrisdale Project, CIVIL 598 Project, University of British Columbia, Vancouver, 1999 Goranson, S.G., Activity Survey Impact on Construction Productivity, American Association of Cost Engineers, Transactions, 1988, pp. H1.1-H1.6 Hancher, D.E. and Abd-Elkhalek, A., The Effect of Hot Weather on Construction Labor Productivity and Costs, Cost Engineering; Morgantown; Apr 1998, pp. 32-36 Hanna, A.S. and Heale, D.G., Factors Affecting Construction Productivity: Newfoundland Versus Rest Of Canada, Journal of Civil Engineering, V21, n4, Aug. 1994, pp. 663-673 Hanna, A.S., Peterson, P., Dettwiler, J., Russell, J.S., and Gunduz, M., Assessment of Global Impact of Change Orders on Electrical and Mechanical Construction - 8Approach, Construction Congress VI, Orlando, Florida, 2000, pp. 1177-1188 Hanna, A.S., Russell, J.S. and Thomack, D. Quantifying the Effect of Change Orders on Electrical Construction Labor Efficiency, Cost Engineering; Morgantown; Feb 1998, pp. 36-41 Huang, R. and Halpin, D. W., Graphical-Based Method for Transient Evaluation of Construction Operations, Journal of Construction Engineering and Management, Vol. 121, No. 2, June 1995, pp. 222-229 Ibbs, C.W., Quantitative Impacts of Project Change: Size Issues, Journal of Construction Engineering and Management, Vol. 123, No. 3, September 1997, pp. 308-311 Jergeas, G.F. andHartman, F.T., Contractors' Construction-Claims Avoidance, Journal of Construction Engineering and Management, Vol. 120, No. 3, September 1994, pp. 553-560 Kallo, G.G., Estimating Loss of Productivity Claims, Journal of Management in Engineering, Nov/Dec 1996, pp. 14-15 Kannan, G., Time-Lapse Video Applications for Construction Management, Discussion by Govindan Kannan, Journal of Construction Engineering and Management, July/Avgust 1999, pp. 293-294 Kartam, S., Generic Methodology for Analyzing Delay Claims, Journal of Construction Engineering and Management, Vol. 125, No. 6, November/December, 1999,409-419 Kellogg, J.C, Howell, G.E. and Taylor, D.C., Hierarchy Model of Construction Productivity, Journal of the Construction Division, Vol. 107, No. COl, March, 1981, pp. 137-152 Kim, Y., Organizational Assessment for Construction Productivity Improvement, American Association of Cost Engineers, Transactions, 1993, pp. 215-225 Knoke, J.R., Avoiding delay claims with automated schedule reviews, Computing-in-Civil-Engineering-(New-York).v 2 1995, ASCE, New York, NY, USA. pp. 1506-1512. Koehn, E. and Brown, G., Climatic Effects on Construction, Journal of Construction Engineering and Management, Vol. 111, No. 2, June, 1985, pp. 129-137 Kuprenas, J.A. and Songer, D., An Optimization Methodology for Crew Assignment Based on Maximizing Labor Productivity, Computing in Civil Engineering, 1992, pp. 182-189 Larew, R.E., Construction Productivity: Continuous Improvement is Normal. Transactions of American Association of Cost Engineers American Association of Cost Engineers International; Morgantown, 1996, pp. PROD.4.1-PROD.4.5 Laufer, A., On Site Performance Improvement Programs, Journal of Construction Engineering and Management, Vol. I l l , No. 1, March 1985, pp. 82-97 Leonard, C.A., Fazio, P. and Moselhi, O., Construction Productivity: Major Causes of Impact, American Association of Cost Engineers, Transactions, 1988, pp. C3.1-C3.5 Liou, F. and Borcherding, J.D., Work Sampling Can Predict Unit Rate Productivity, Journal of Construction Engineering and Management, Vol. 112, No. 1, March 1986, pp. 90-103 Liu, L.Y., Digital Data-Collection Device for Construction Site Documentation, Computing-in-Civil-Engineering-(New-York).v 2 1995, ASCE, New York, NY, USA. pp. 1287-1293. Liu, L.Y., Stumpf, A.L. and Kim, S.S., Applying Multimedia Technology to Project Control, Computing-in-Civil-Engineering-(New-York).n 1 1994, Publ by ASCE, New York, NY, USA. pp. 608-613. Logcher, R.D. and Collins, W.W., Management Impacts on Labor Productivity, Journal of the Construction Division, Vol 104, No. C04, December, 1978, pp. 447-461 Maloney, W.F. and McFillen, J.M., Valence of and Satisfaction with Job Outcomes, Journal of Construction Engineering and Management, Vol. I l l , No. 1, March, 1985, pp. 53-73 189 Maloney, W.F., Productivity Improvement: The Influence of Labor, Journal of Construction Engineering and Management, Vol. 109, No. 3, September, 1983, pp.321-334 McCullouch, B.G. and Gunn, P., Construction Field Data Acquisition with Pen-Based Computers, Journal of Construction Engineering and Management, Vol. 119, No. 2,Junel993, pp. 374-384 Moselhi, O., Estimating the Cost of Change Orders, Transactions of American Association of Cost Engineers International; Morgantown; 1998, pp. ES21-ES25 Moselhi, O., Leonard, C. and Fazio, P., Impact of Change Orders on Construction Productivity, Canadian Journal of Civil Engineering, 1991, pp. 484-492, Noor, I., Measuring Construction Labor Productivity By Daily Visits, Transactions of American Association of Cost Engineers International; Morgantown; 1998, pp. PR. 16-PR.23 Oglesby, C.H., Parker, H.W. and Howell, G.A., Productivity Improvement in Construction, New York : McGraw-Hill, 1989 Paulson, B.C., Chan, W.T. and Koo, C.C., Construction Operations Simulation by Microcomputer, Journal of Construction Engineering and Management, v 113 n 2 Jun 1987, pp. 302-314. Pogorilich, D.A., Daily report as a job management tool, Cost Engineering^ 34 n 2 Feb 1992, pp. 23-25 Portas, J. and AbouRizk, S. Neural Network Model for Estimating Construction Productivity, Journal of Construction Engineering and Management, Vol. 123, No. 4, December 1997, pp. 399-410 Rowings, J.E. and Somnez, R. Labour Productivity Modeling With Neural Networks, American Association of Cost Engineers. Transactions, 1996, pp. PROD. 1.1-PROD. 1.3 Russell, A.D., Computerized Daily Site Reporting, Journal of Construction Engineering and Management, Vol. 119, No. 2, June 1993, pp. 385-402 Ryser, R.L., Construction Productivity "A Measurement of Worker Efficiency?" (http://www.proiectmgmt.com/CP.HTMX 1999 Ryser, R.L., Scope Definition and Control, http://www.proiectmgmt.com/CP.HTM, 1999 Sanders, S.R. and Thomas, R.H., Factors Affecting Masonry-Labor Productivity, Journal of Construction Engineering and Management, Vol. 117, No. 4, December, 1991, pp. 626-644 190 Sanvido, V.E. and Paulson, B.C., Site-Level Construction Information System, Journal of Construction Engineering and Management, Vol. 118, No. 4, December 1992, pp. 701-715 Sanvido, V.E., Conceptual Construction Process Model, Journal of Construction Engineering and Management, Vol. 114, No. 2, June, 1988, pp. 295-310 Semple, C , Hartman, F.T. and Jergeas, G., Construction Claims and Disputes: Causes and Cost/Time Overruns, Journal of Construction Engineering and Management, Vol. 120, No. 4, December 1994, pp. 785-795 Sonmez, R. and Rowings, J.E., Construction Labor Productivity Modeling with Neural Networks, Journal of Construction Engineering and Management, Vol. 124, No. 6, November/December 1998, pp. 498-504 Stukhart, G., Bar Codes and Data Integration In Construction, Computing in Civil Engineering, 1992, pp. 484-491 Tavakoli, A., Productivity Analysis of Construction Operations, Journal of Construction Engineering and Management, Vol. I l l , No. 1, March, 1985, pp. 31-39 Thomas, R.H. and Holland, M.P., Work Sampling Programs: Comparative Analysis, Journal of the Construction Division, Vol. 106, No. C04, December, 1980, pp. 519-534 Thomas, R.H., Mathews, C T . and Ward, J.G., Learning Curve Models of Construction Productivity, Journal of Construction Management, Vol. 112, No. 2, June 1986, pp. 245-257 Thomas, R.H. and Yiakoumis, I., Factor Model of Construction Productivity, Journal of Construction Engineering and Management, v 113 n 4 Dec 1987, pp. 632-639 Thomas, R.H., Sanvido, V.E. and Sanders, S.R., Impact of Material Management on Productivity - a Case Study, Journal of Construction Engineering and Management, 1989, pp. 370-384 Thomas, R.H., Loss of Construction Labor Productivity, Due to Inefficiencies and Disruptions: the Weight of an Expert Opinion. Rep., Pennsylvania Transport Inst, Perm State Univ., Univ. Park Pa., 1990, pp. 91-98, Thomas, R.H, Maloney, W.F., Arbor, A., Horner, M.W., Smith, G.R., Handa, V.K., and Sanders, S.R., Modeling Construction Labor Productivity, Journal of Construction Engineering and Management, Vol. 116, No. 4, December 1990, pp. 705-726 Thomas, R.H., Labor Productivity and Work Sampling: The Bottom Line, Journal of Construction Engineering and Management, Vol. 117, No. 3, September 1991, pp. 423-444 191 Thomas, R.H., Effects of Scheduled Overtime on Labor Productivity, Journal of Construction Engineering and Management, Vol 118, No. 1, March, 1992, pp. 181 -188 Thomas, R.H., Sanders, S.R. and Bilal, S., Comparison of Labour Productivity, Journal of Construction Engineering and Management, Vol. 118, No.4, December, 1992, pp. 635-650 Thomas, R.H and Sakarcan A.S., Forecasting Labor Productivity Using Factor Model, Journal of Construction Engineering and Management, Vol. 120, No. 1, March 1994, pp. 228-239 Thomas, R.H. and Napolitan, C.L., Quantitative Effects of Construction Changes on Labor Productivity, Journal of Construction Engineering and Management, Vol. 121, No. 3, September 1995, pp. 290-296 Thomas, R.H. and Oloufa, A. A., Labour Productivity, Disruptions, and the Ripple Effect, Cost Engineering, Vol 37/No. 12, December 1995, pp. 49-54 Thomas, R.H. and Raynar, K.A., Scheduled Overtime and Labour Productivity: Quantitative Analysis, Journal of Construction Engineering and Management, Vol. 123, No. 2, Junel997, pp. 181-188 Thomas, R.H., Riley, D.R. and Sanvido, V.E., Loss of Labor Productivity due to Delivery Methods and Weather, Journal of Construction Engineering and Management, Vol. 125, No. 1, January/February 1999, pp. 39-46 Thomas, R.H. and Zavrski, I., Construction Baseline Productivity: Theory and Practice, Journal of Construction Engineering and Management / September/October 1999 pp. 295-303 Vanegas, J.A. and Halpin, D. W., Use of Construction Simulation in Claims Analysis, Computing in Civil Engineering, 1992, pp. 1207-1214 Veenendaal, J.A., Analyzing the Impact of Change Orders on A Schedule, Cost Engineering; Morgantown; Sep 1998, pp.33-39 Wideman, R.M., A Pragmatic Approach To Using Resource Loading, Production, and Learning Curves on Construction Projects, Canadian Journal of Civil Engineering, V21, n6, Dec. 1994, pp. 939-953 Willenbrock, J.H., Thomas, R.H. and Francis, P.J., Factors Affecting Outage Construction Efficiency, Journal of Construction Engineering and Management, Vol. 113, No. 1, March, 1987, pp. 99-116 Williams, T.P., Applying Portable Computing and Hypermedia to Construction, Journal of Management in Engineering, Vol. 10, No. 3, 1994, pp. 41-45 192 Williams, T.P., Hypertext Data Base Applications in Construction, Journal of Construction Engineering and Management, Vol. 117, No. 3, September 1991, pp. 460-467 Zack, J.Jr., Claims prevention: Offense versus defense, Cost Engineering; Morgantown; Jul 1997, pp. 23-28 Zink, D.A., Impacts and Construction Inefficiency, Cost Engineering; Morgantown; Nov 1990, pp. 21-23 193 APPENDIX 1 Logic (activity code, description and type, production data, and predecessors); Early start time bar chart; Hand-made schedule by the forming and contract placing subcontractor's superintendent. CJ a. w ei si Ms a H O W o Bi A. Z o H •< .2 "3 " IS J is e zz e e 3= e z r a= ee ee ZZ e zz e ZZ ZZ 3= ZZ eeee ZZ ZZ ee VtDOtDtDtD.DBKDCOtD CD CO CD era co m psi e C ee ee e e t— §—loiait— i— t— n ex! 2= e ES ee «— ro 2Z e CO CO § § ! § z r z : ee - E E E E E E E E f e E £ £ E E E E *- £ E E E E E E E E E E 3 = U X u u f) — • a -o tu y < 2 3 := S f i p tj o CO iH u i <o Oj CJ —• g 5 « S OJ *S "J^  j? — u — e: 5 y =118 f a ? i I set ft3 .s s u 8 S3 8 3 QJ 'lA eter strip 1 eter strip 1 K 1 c c **_ o OJ e _JE oj OJ CL. CU 1 2 c3,3 Bulk excava Install dew •si 8? .£* .2 CA 3 3 -5c2 £ 3 CP CP CO CO CO * fst CO CO 38813858B838 - § ro 5 r3 f3 r*J > *-* co co cn CP cs CD co _ -a -a 3 8 8 8 8 8 CO eo oa —t CD CD —• "T1 c o c o CD CD CD CD CD CXI CD CD CD CD CD c o r o c o c D CD LO CD CO e a i n c p INI CD d £2 iZ CO to E E E E ESSE E E E E iZ E oo oo to co OO C M U -oo oo oo co Ci. OO Ck. C L . oo oo oo 3 z= z: e e OO to r-J rsi r*j z: e z: c/s ro eg~-•ZZ ro E S CO 3= z: e e n r u ' E E z: zr ee z; e e CJ i£E oo o et:E oo o z: ua oo z: ro C J 3- E E E £ £ £ E E £ E E E E E E E E E E E E • " E E E - E E E - E E E E z: sr z: oo oo oo z; zz z; z= z=z: z: z; ar ae zr zr zr 3=; 3 I S e E E E e e e e e e e e e e e e e et VL z* LO -a U = l 1 C J to 1 •3 'tn 1 CD en (U e » CO HI — • -I i to c/t — cn M CO 01 fc. en vt ' 2» PI 1 cn cn s b i s £ B J. "* *Z u II ^ T * 3 £ Ilf Is o «— , ° fa OJ .2 u cn-— w C Si c 11 1 ° s § — u B * *• J5-S ill g 8 S cu CU *-s U O co U s CO *. co Tl u CU !%* u O CJ 3§ CO c_> o JX: O 3 c2 i i i II L 3 C £ c3 c^ r laa. » III c 2 i s c2 1 i <z> S 8 CD CD 5 ks r »1 •S 'SJ i L . a I B i -— QJ 3-i- b , - 8 bL i T l 1 ' O- S ft- ~> c 1 5 =3 =S • CO CD 5E5 SRi 3 3 rS S S CD CD CD CD cS CD CD CD CD CD CP CD CD C P CD CD CD CD § 3 SS CD CD CD Co CD CD CD CO CD CD CD e E E g . «P v v I E E E e e e ± e e i e XT cu U CO rorMw e t; s s , v f v ... z= ca ca u f n N j 4 e " ro *NI P I N H i t i I I I ro ^ rp f>J j-« oo co cc i 2 2 I i l I I l I cn S g I s c3 cn 2 S. S 3 <2 s S a •a <2 <_> OO OO ex. c t ; Ck. CU c c c c CL. b. CD CD CD CD ro CD CD cn s .-CD CD oo oo a s s s 2 S CU 3 S3 S cu CL. cS B y o H: cb u 196 ( 197 m Nrno mnn C O I ^ T H cocnin cncocDtD - . n r-J m r»J m rsi m C D C O C D C D C O co co m C D C D C D C O C O co C D C D ro O J n n fcSSfce eeet2S3S3 K31: S3 e S3 fc S2 £ e e e e e ~ Cf2J2 e e e e e I2iz\f2ii:i2t: e e e e e e e e °- e e e e - - - E — E E * - E E - E E — E E E E E »-•-•- — — •- — £ * - ~ E — E - E E E E — - — -m m m i . , m ^.u* " " i / . 1 " - " " " m m " " " * r r f rll *32 r f ? f r f r f f r r f f r r | f r | | ?gs r | ? *r*rB r r ? r ^ • • i l l s 33=3 i i * siiiSH s i i i i B B S ia? iat sl# BiaSs s i s aB i I I I § i i i i i i in §11145 nmm. i i ? l i s in i i i i i I S I I I I c o c o a s : c^pjeo t/*.»cvj S " S f f S ? = = 52 525252525252:5 £2*252 526252 £3 5252 £52 52 52 <j S2S2S2£2S2£2 S S S J 5 5 5 5 5 5 5 5 5 £-5551515 5 5 § 5 5 = 5 & £ 5 5 S 5 £ ? $ $£555 £5555= a £5££5gEg£gs£ ^ S l ^ - f c 5*55 5 5 5 i r i i ; £ 5 5 5 . 5 , 3 5 5 5 5 5 5 5 > & : 55c*. u . c _ u . a . iu_ c*. t^ .»- c~ r*. u. u. t*. c~ Ssi§i3 SiS s S l ss§ i l i l i C D C D C D C O C O C D C D C D C D C D C D C D C D C D C O C O C D C D i | i i i i i i 5I9SSE 3 CD CD CD CD CD CO CO CD CD CD CD CO CD i / ) t n i / i r o r o m c o i w u i u"> iniAi/i • ro ro r 0 . 0 . 0 . i i i m rsi«—<• Ck.Ck.Ck. i i i m rsJ Ck.Ck.Ck. 1 1 1 ck.Ck.Ck. i n Ck. Ck. » ck.Ck.Ck. t i • ck.Ck.cw ck.Ck.Ck. Ck.ck.Ck. ro csi Ck.Ck.Ck. i i I P3- P3 I o 1 JSC o 2 i o 1 Forwork JC o 1 Lk. o I - x t-o i O 1 JM (-. i - - - - - - — O O O o 5 s -X £2 8 U 3 198 ar rsi 2= ar C D C D = - = C D C D C D C D C D C D ro C D C D C D ro Cw e e : 5 kO L O stage S en J | u 1 —• E» co co i S*C!» 3 C O = a--=s a 3 .2 s as-CD CO 3 1 3 CW -s. Pkde Pkde ext co co 3 3 - 3 Ck. Ck. U C O C O C O U O J J O J O C O o o o cc OJ E>_ Ck. Ck. cc cc ce ee*^cc a C D C D C D to C D rsi ro rsi ro rsi ro C D C D L O 3 CO CO CO CO CO CO (J_ CO Cu CO U . . C M C M C M CO C M CO C M CO C M CO C • E E E E - - - - - - - -ar rsi ar rsi ar rsi C D rM rsi rsi rsj C D L O C D L O C D C D C D C D C D C D FDN SS ELS ar e E E E E rsi rsi rsi ar « - » - = - e -£ ~ E ; 2 K S CO CO rM ro rsi r o rsi r o c o C D koto rsi O J t o c o c o - £ E E 51" ' -a , co co oj 3 3 I Ck. Ck. o o o o •a . " . • C3 — — t- 3 c o eo co = o o — -s. Ct. CL. CL. L . S B CC CC CO LO kO kD ^ vXI vO cn co co OJ OJ vO •<-» c n t n OJ OJ cn cn in u a) m c n « id co T -4-» -•-» »a -4-> — * M ' ' I I * ' « N n H S ' aiSss a sM J CO as J o c. J c k T c L O . o J * * - r-- r-— >« • cn T co T CA — E n ~— r— ab-stj side f l id C O cn OJ cn c/t "•a - . — C O M Is •VI 1 a-e, ac Vails -cols -cores -et util OJ 1 8 CO OJ Ck, S CO CO CO 31 3 3 3 e > C U C X . Ck. C O C O C O C O o o O O C O o o o — Sis ccccec c i -M» co co u co e n r co co c n w ra ta « itj y i I I i i 8 8 8 8 § i — — c <-» — o VI «J ™ II s i t 3 S ? g 5j S S ™ S S o a S S c N I N I cones C D C D ID C D C D C D C D C D C O C O C I S S rt rs? S m ™ cn CIO eg cso C D S L D J2 cp iS En to vS r— ^ 5* S ro •> KJWHWH raa an w w w s W X ^ W B R J W W s s ) C D C D C D C D C O C D C D C O C O C D C D C D C D C D C D O S C D C D C D C D O D C O C D O C a r o <r g i LO LO LO LO LO LO CO LO LO LO LO LO rsi Se • CO Is CO ~.rtrt CD CO rt rt CD CD rt rt CD CD CD OD CD CD C O 1 1 1 1 ro I S J -r-m rvi ro rsi i ro i ro Ck. ex. ex. •— rsi rt ck. C L . rsi rt i t rsi rt CL. Ck. rsi —i rsj 1 rsi Ck. —; CO CO CO c o CO CO Ck. (3 cc -X o 2 t. o ? c2 oe o 2 oc i C o 2 C je a 2 OC c o o I s. oc i C o i c2 '5 1 1 a g _ - - - - - - -CO Ck. c^ -o <r> O o CP <r> o o o 8 CO 3 5§ Ck. Ck. a CO 3 Ck. !2 8 CO 3 5? a co 3 3 1 Vt Vt '5 S 3 S 2 a 199 tz LO CO I z : z : e e e e e § g e 3 = CD CU CO LO UJ CO L*J CO CO CO GPRJ 3 £9 CU CO CU CO o rsj rsi t-J CD CD CD CD CD CO no CD CD CO CD r— PLOCREL SITE FS S3 e co co CO u. 3 = a= e e co CO e £3 e FDN SS CO CO ac CO e co CO CO CO CO SITEFS e & SITE FS s SITEFS e 3 SITE FS e & e £5 GPRJ FS GPRJ FS GPRJ FS SITE SS E E £ £ £ £ £ £ *— - £ £ £ 3 = £ £ £ £ £ £ £ £ £ * * I J « M a 1 - i i •s -s ' a . '5 1 B . « . 2 • § « = § If = § I 1 i § S § t * 5 | % 1 1 1 1 t 1 1 i l l l l l E l i l i 2 I I I I I I I i ^ I 201 202 203 SOOO JAN 3- 9 10-1 to 1 • sc l> 1 o» JO s 3- 9 10-JAN 2000 . DECEMBER - 5 6-12 13-19 20-26 27-cn ir II - 5 6-12 13-19 20-26 27-DECEMBER NOVEMBER 1- 7 8-14 15-21 22-28 Ii" 2 in o_ •VI • CJ \ o. 1- 7 8-14 15-21 22-28 NOVEMBER OCTOBER 4-10 11-17 18-24 25-31 F/fl/P 4-10 11-17 18-24 25-31 OCTOBER 1999 SEPTEMBER - 5 6-12 13-19 20-26 - 5 6-12 13-19 20-26 SEPTEMBER 1999 AUGUST 2- 8 9-15 16-22 23-29 2- 8 9-15 16-22 23-29 AUGUST JULY 5-11 12-18 19-25 26-5-11 12-18 19-25 26-JULY JUNE - 6 7-13 14-20 21-27 - — — — - 6 7-13 14-20 21-27 JUNE tu 8 O O CD O O O m cn j? 2 8 i. Pi- w (ot>i>4-di*G 1 ] Y 5.S. - 2 W . ^ 7 RAtn-Tfar.lo / ^ i . - ^ . ^ 7/<yu-. I ^9.%^? 205 206 - Oct, 1-7, %%/^J)yLnri 3. & r ^ - ; . c 5 . 6 : ^ a r . 7 • fair • I ft '> . _ J» % * . f l r . J u J . ~ ?>/$W P A X . Xfi , c i v " sr.4,7 207 APPENDIX 2 Daily site problem sources report; Work environment report. t 2 0 U S a e r- 0 - « (- S u a u 3 i-, o 0 9 cc A 0. Pi Z H O E< a cc u be 8. s S 3 J o *~ © 5 III I f g : * *2 *Z j= •e * •> o. o u * * * > gaa-s >-. •sis. is ii J < > Jt3 o • e: M o -as 1 «=» t « g; *" ^ 3 •• ^ n & SS *-* i t; "2 XI - « M O *•* O xis.-3.-zs. o 3 g I 3 *" | § 2* 13 o «_> c 0 3 w A O O O O O O O O O O O O O O O O O O O O O O O O O ^ O O O O O O O O O O u i - i j , o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o S S 2 2 S ° 2 S 2 2 S 2 2 2 2 2 S 2 " 2 ° 2 S 2 S 2 ^ " " o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o S S S S S S S S S S S S S S S S S S S S S S S S S S S S o S S S S S S S S S g g g g g g S S S g g g g g 8 S g g g S S g g g g S o S g g S g g g g g g S M —• —' _ 3 = = 3 =• •ST! 1 - g T j l c c c c 1 > 3 % Z, *? s • s i = h* e t-J ;» .MriiiiiliifffllKiiiiiiiiSiiiSiJilt!!.-llllililsllillllllillllllSlliiliiilii! S S S S S S S S S o S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S I l l l l l l l l l l l l l l l l l l i l l l l l l l l l l l l l l l l l l l l 0. : 209 ^ 5 S S 2 2 2 2 2 2 2 2 2 S 2 2 2 2 2 2 0 S 8 o o § 0 0 0 0 0 , 0 0 o o o o o o o o o o o o o d o o o o o ^ H ^ ^ c r ^ o o o o o l l M « m « * i ^ « ^ « r t 2 2 2 S S S 2 2 2 2 2 2 2 2 S S K 2 ° i 2 2 2 w - . , . ^ ^ ^ r ^ < - ; ~ C 3 1 < - > ' " * ^ ^ ' " " ' ' " " ' 0 OOOOOOOOOOOOOOOOOOO^MvacpHOOOOO o o 0 0 0 O O O O O OO 0 0 OO * o o o o o o o o o o * o o o o o o o o o o o o o o o o o o o o O O O O O O O O O O 3 8 g 8 8 g 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 11 | g 8 § § § § g S 8 S S 8 S 8 8 8 8 8 g g g g g 8 8 8 8 o o S o a o o g S a s s & 1 = 5 1 II £ 0 1 1 g > u o CL m 11 -iiii IfflfffiffiifillliiiiillHil : | s s s s s s s s s s s s s s s s s s s s s s s s s s s s s s . u .-» . - • .WJ « J «o .-» • .b* cn <v> <v> Cr> I « « • O 9* *4 ^ 4 ^4 ^4 JJ( jW Jtf M .jjrf t_J ZZ> 1 3 -«- C IM > o * £ *• 5 w <a n —« « u •» o M fi. U : § : S £ 5 s ; U. lo. U. M ki In k I M U> h. I § § S S g g S 8 g g 8 8 S S S S g 8 S 8 8 S g S S S 8 S g u o o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 §2 i o o o s ? s ! •a <w *g •* 0 o 0 0 X JS K JC M Vt MM o 0 0 3 3 I I T J T J c «= 1 s-o o o 5 o S S 2--S 2--g ii 5 : ; : ; «.•£ s i Z f 5 a i I A t -= -e * o> o c> o cf> S * 2 * £ * w e O JC O J= -~ o - J o *• <a _ *- — ~cL : : j : J ; o>; 5 s t s a * : *- « *• o •> o o A- • H z H z a M a E 0 * O Z* • C "in C a o n I s s K — K _ - 3 Z 3 S S IB o o 0 0 s s s s g o 0 0 3 S II <=> o 0 0 DO T 0 ! S S a : 5 g 8 8 8 8 8 g g S S g 1 I — 4 0 o o o c r > > * o o — « M o o o o C t « o o < « —« o> 0«3I <u —• ti* « <n c» 1 • ' • a j a m m a r * ' ! *. —• *- «t • « m < - 4 « •<» <j»o>« * < ** •» « ^ -S" c* J* "t i? *^ J 5 3 S « o < : s a s 3 > s : s V* Vt Vt S> fci — —• oc —^ -« •> o -S O O (J CL O-"o e2 «2 «2 n S S 5 o o o o o o o o o o o s s s s s s s s s s U. I>. h. h. k. k. 8 8 § O o 8 o 8 § 0 (M0}17\O<OIN0\OrHfM O O O O O O O O O O 210 ^ o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o ! " i S S S 0 0 0 0 0 0 0 o o o o o o o o o o O O O O O O O O O O O O O O o o o o o o o o o o o o o o o o ***• o o o . o o o o o d o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o d O O * O O O O O O O O O O O O O O O O O O O O O O O O 3 g g g g g g g g g g g g g g g p Ig g g g g g g g g g g g g g g g S g g g g g g g g g s g g g g g g g g g g S O O O O O O O O O O O O O O o o o o g g g g g g 8 8 8 8 t s . 1 11 '. O O O O O O l I O O O O O O —I —• = 5 s S ? s = : s 5 s s 11?? ! ! ! I I ! i n i l ! . . r> ^ o o - - - - j J J J J K J * j« i l i l i i i l l I i l l i l i i i l l i l i l • o o o c i < < o ^ "S <o M » < O O O O O O O O O O O e i M k . k k . a => oa M M «— < — > v . i < - » ~ u . w . « « . « « . i * . u . S *• CM o* o- * • **» • _ #L *• ' t » •* v &• ©> * cn •> O* cn i « V » » j a j a c « * j « » id —' *> u i <3« « *- •» . tl ' "5*1 * « « ^ • ^7^ , ' ^ 7 - -w > » * < # c » « » » c « O T j » * « ; « r t > > v - - - - - - ? | = 1 I 111 l l l l l l l l i l i n 5 i | i f til i ; I i : J 1 I I ! ! l i h I * i : : < i : l i I i ! I l l J M I J I I I J H l I f M i l = - « M I ! M M 2* u U J n « « ©* o» i • ^ « ^ M * J S « I w 2 « v a w n « v i V > n > ~vi * m • • « i vt « u h. K O X •»* O O -« —> o w o ix. a. •— o. o ca. n. 4. M in VI x in o — O O O O S . J s O ^ SSSSS s-e-S s o > o 1 1 2 •s J i i i i i i i i i i s . I JllJJiJJJll ^ i i i i l i l i i l i I ' S s S S i i s i S i s IfIJ1IIIIIIII II i i ! ! ! ! ! ! ! ! ! J i j S i E i S S S S E S S S S S S i S S S 8 S S 2 2 S 2 2 S ! g S S S S S S S S 8 S S S S S S S ss s s s s s s s s s O r t O O r 4 « * « r s i m < » t « * t ( * t < * « * r i r v W O O «-• .-«0»-<«''«**»«"> ,^ -^ ,C> 8 -lHINNMNrCNNNNNMCNNlJ- S S 3 E f 2 J £ f E ! E i J S ! C O O O O O O O O O O O O O O O O O O O O O O O O O O O O o o o o o o o o o o S S S 5 S S 2 S S 2 2 2 S II § § 8 8 § § ° § ° § ° O O O O O O O O O O O O O 211 r i l l l l i l l l l l l l l l l i i i i i l ls i l l is i i l l l l l l i i i issss §I§i§IiI§iIiII5§IIs§i§i§II|Iii5 i l l i l s l i l l l l P = «=! i i i i 11 • I l l l f f l l l l l l l l l l l l l l l l l l l l f l l l l l l l l l l l l l l l l i i • m m m a a . a . a . a . : o o o o . 0 0 0 0 % % % « f i l l TJ TJ TJ TJ .C JS -C J= » > > > I l l s o u o o • 1J « • « • ) • ) • « • 8 « o 8 ' cn * • « V . TJ TJ -° £ a£ ' : 5 S S £ -ls;^!!!!ii!!!!!iH^ UJ < i g s g § g g s § g | | s § s | s § g § g | | i § s § | | s p i § i o § | | s g 5 » ^ ^ w * o o ^ ^ o o ^ « £ 2 « ^ * £ £ n i 3 . £ « K S K « ^ « ^ 8 S 3 S S S 3 o o 8 S o S S S o S o S S S o 0 0 0 0 0 0 0 d o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o o 0 0 o o 0 0 0 0 0 0 0 <w « <a <o « •» « *» > > > > • > > o u u u u u u M (S UJ UJ U» UJ U l 5 . •> 3 I e m £ TJ * « *• j S 2 5 £ ; : § z* o o o o o i " o ** j O T I 5 * c c £ •> 3 3 •= c _ 3 a o o M =» S S - ; = = § * * O * 3 3 O 8 8. « 2 S O Z M « V) » • - « l3 X £ £ W jS £ C C C C B C C O O O O O O O aj JB «t a m « J > > > > > > > a <o a « «j <o o 1* 0 0 0 0 0 K S JJ S j< .M .w x "3 "3 _"3 "3 *3 15 ^ O O O O O O O S it o, o. a. o. o. O O O O O O O O O O O O O O O O O O O O O 1 8 i i 11111 212 O d I t-» o o S3 ~ 'I IO O 1 g o o o 2 S 2 2 2 2 2 2 2 2 2 S ° S ° o o o o o o o o o o o o o d d d o o o o o o o o o d d c> d c> c> d d d d d d d d o d o d o o o o S l C S S S S S 0 0 O O <=> O O O O O O O O O O O O O O o . . . . . . . . . . . . . . * " ! . . . * " ! " ! *"? *"! *** rtrtrt«si «si o o o o o o o o o o o o o o o o o o o o o o o d d d Q ^  Q g Q § s o *| .2 -2 N U U M «C t_» o o < 3 3 o o '•>>'< I « « I ' U U i . K K I s a a s • - • M O O o o o O o o " Ul Ul S S " o o s 8 S 8 8 8 0 0 0 0 M n M r ! f v n S S S S S S S S S S S S o o o o s s : 8 S 2 S 2 S S 0 . 5 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o o o o o o o o o o 0 0 0 0 0 0 0 0 0 0 0 0 «3 ts tz C B C C C e a c e c c c c c r~ •2-2-2 o ^ o ^ o o o o o 0 0 0 0 0 5 S S S 8 S 2 S S 5 S C 2 5 S S 5 S S S S 3 S S S S S S 5 «5 5 g g o o o o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 • 2 ^ 3 g. ° g> o -o fijr* o -n u « *• * * O cr» «J o ( I g . o e t . • c*> J3 mr o S- —« o u o TJ O C — &*£| r:= c e o 5 H «£ - j ~2 o <o o o u -p £ S « „ fr 5 £• - S £ £ ^ ; g - | £ o u p" c • « o e s s : ?g-s = = - 5- T:T: s a s t; & % % i <—t t-i sc •» «/» v» w» > > o o J > « m JTJT o o "S "5 c g * > 12 e c o o 2 3 a tz o o o o c * S e * 5 S °* S o 2L, • I Hx 1 s . | £ ~ g-c •> <- ~" •> O J- fc. O M CM "2 o « 6 m I S s I s s •» O «t M O * w .£ o •> o o <* — o • rt O M o fc, £ * • " •> o> O O t> o*o o > « >n > «j « £ » S.9H i i US 5 g ^ ° S ; f "S S o *S 2 o o l i s 5 — M -O rt M -o o 'So* *« O »- _ > o > o •grtS " S r t 5 -M - S "tl rt S o « > 0 « > * 0 * a -X s * s £ £ 5 £ II o o o c o « W « «l w o f * o ^ «> o > c— a , ^ . > c— a . ^ • M CM: »- CT«C»M « c ^ a — • o « « — < o *-* « . " I s . s l = s s . . —« o • • o u —• a o> : c : 0 u hi • co • o a: cu m i??il!l!iIII?^??lH!{ ill! siiiiliHJ III s s s s S S S S S S S S S S S S 3 S S S S S S S S S S S 2 C S 2 i 2 2 8 g a S g | B g g S E S B S S S S g | E III? ilillliilllililliililll ill III 11 III l l II C< Cf» * o« o» « •> o» « to « * J m «* rt n S rt o « o o « u K u o SK o . a . a . cu a . O O O O C k S S S S O O O O O O j o j o r - ji> o o o o •— « 8 o o o> ? ^ *o o f CP u w 3 — •> *> S S Si "3 vi cy» u «/» cj O ^ O S 11 a CM k 2 k S O O O «-» « u» a: o. Ck. S o 0 0 0 o 0 0 0 c i n o o o 0 0 0 213 ~3 O o o o o o o o o o o o o o o o o o 2 2 2 2 2 2 2 2 S I a «<«SI <N> P*.^p4,4.^vri_«_i,-tr-a*H<-l~4<~l>-4*'* . . . . . . . . . I . O d d c > o d d c > d d d d d d o c > c > d c > d o o o o o o o o • o> I «— <=> o o o o o o o o o o o o o o o o o 2 2 2 2 2 2 2 2 2 • S " i d d o d o o d d d o ' d o ' d d o ' d d d o o o o o o o o o » * > S S S S S S S S S S S S S 8 8 8 8 8 8 8 j 8 ; o ~ » — — — — .«: — — — — — — ^ ^ " ™ -* ~* : s t *™ • — , 5 8 S 8 8 8 8 S 8 S 8 S S S S S S S S S 8 8 8: a o i c c c c c c c e c «t c c « S • •1 1 i s i i i i i i i i i i i l l s i l l s i i l s ' s o o X K O K X C J O X X X O O O X X * £/S 5 > o o 5 H 2 2 | » ^ * ^ .3 .3 S-3 ex, «> ~O T3 j£ J-J ui on o « « i « «o 5 o>" o « w «D «o « <a <= • C * * *• » •» aQ O *-> P «J « «0 «0 S £ g g g - - - -n n «i « 3 2 S M j» 2 > e ^ ^ ^ w tj» »* e» u= - -e .*= C O C O * - ' * ' *>*J —• o —• o > «v. > C C C C o o o o o o • •> m * •> u. «> *. n n « v i u, o b O u. u, u. UJ u u o o o o fil S ! | | * *" u o O o m c M C K K x x S 9 S 9 * W o —> o —• o o p o u o u o > > S > < u < t> *- t- *»- t-TJ TJ TJ UJ Ul UJ J= J= .C « <a « s i s m n n • w « £ ^ £ ooo o o > > X x > > 5 TJ TJ TJ >3 .*= .*= « « •« •*£ =:=:-is s s s . n « n o HI I e c c u TJ TJ 3 3 JZ JZ o o o o o 5 o o > > > 1 > > X K X *J J* Jj S o o J5 ! f * ffiiiiijtniifil Ifiliiiil Iii i iiiitiiiiiiiliij lliJlllis III I J i i i iHil l i l i l l l S i l l i H I l is, . . . . . . . . . . :tjg 5 l | 5 E 5 S 2 2 H | | 2 = g S S g g B 5 B E 2 g g ' • l s i l l l l l l l l l l l l l l l I l l l l l l l l 'i:""s""I""i"""8 o o . n o o u n o o o o o o o o o o o d d o o o o o o o o o o o o o o o o o . n o o • » o o o o o o o o o o o d o o d d o o o o o o o o d o d d 8 8 S S ~ 3 8 8 S S S 8 8 8 8 S S S S 8 S S 8 8 8 S S S t o o o o g g- g g I I I I III I I > — " >>— >>>> -.>>> — 5 £ III III IIII I f i S f i l « I i u S f o ti J T m o a: a. IT I -S3 3 S « u ! «> > ' 5 o —I « •U O > > « JZ •> -I 2L-£ >>1 ^ "S. £ " ! -u> c x 3 *S "3 « * O fi O - •£ J; •u o *i —« x m « w TJ o TJ O O. «= C — cow—> t j 0 3 _ o o* « « o w 5 a. a a ^ a. u ta a -4 o I ^  > •i > u, « O K >. o u o — > - S 3 -u. — j= •» J= >, »J c g — j TJ ~* • * S " * E * - | a i l * - > — I S^llgJI If O «3 O U. ««> Cu, TJOU«>ut«>«->^ 3 " o c T j 3 u y - 5 _ , T j j » » V ui w v i o H e in > I " i s TJ m o * « « w e ' * * . -g j f . . e n t e c O »- «i O O > c • > > S o u X —• —• X X -J I s a 3 3 s (SdSatS ^ » £ «3 ^  * o » c c c c " S c c c " « S E g o o o o luooob o ui o « « « « u < a « « u > > > > s 5 i i s i 5 s U U U U o u u t> u K K K X —XXX— 5^2 * * * * * — • — ^ M. ** J* ~* X*>J>( "3 "3 "3 "3 S"3*3"3S 3_S^ o o o o o o o o o o o o o o o o o o o o o o o o o o S o o o o o o o o o o o o o o o o o o o o o o o o O O O 111 11 1111 ill US O O O OJ N N N M IN CJ M »r>0^ 214 J O O . A ./* O ! *n i ! o o o o .*» O O O O O O O O O J o J 1 o ' 2 * ' 2 J 2 ! ! S S S £ 2 S S 2 £ m£ rs> _ ^ rvi i CD < i o O O rt ^rt—. <o «-i e-> « «-i « r- j j o ! . ! ' ^ i ^ i S o c! d d d ci ! * ! • w ^  ^  o o d o d d d d o d c ) ! «^ • t - 4 j -^  • | d « o i j r t o o o o o o o o J> S M iH tH <M S id d d d d d O O O O oooo«rtOOOO O O O rt -H H H M c o n w r i N n rt rt rt O O o o o o o o o o o ooo<s»oo*to<#* o o o o o o o o o I n o S o o i o o ri co » «o <o • rt : -|1 *- o o o o o J l/J o o o o o o o o o • o o o o o o • o g g g g g g § o o § o o o o o o o o o o o o o o 5 u* c c ££ a o o a 2 CF* w D> D> C S U O S O O Q O -4 K ,C K X= J= .£ o o 0 . 0 0 0 0 0 0 0 0 1 g s. I I - I = 2 " ' 1 IJ U O - rt 5 • o 3 > a > — — O L, O s i J - - - " S °"* S S * 2 t? n Q. Q, CL 3 J-T o —• -— — — O fc. O O O O rt D» > > g> — — —. * o — « « « « —. T) * » > —' *•* •£ 2 rt ° 4u to 8, "o 3< SB £> «/» £ £ 5* s * : 2 o g *• c «t rt rt rt _ a ca « « «« t 2 M r t « r t * 2 * i « ] < f } I gg2rt«3rt«Srtrt fe|0OOO00O S O O o o S S 8 0 0 0 0 0 0 0 mu iflifif S S S S S 5 S S 3 S S S S S -I « ! s: 111 Pi itlllH ISi i i l i iii V i SB SB * * , ••ill ll?'' 11121 H i i H = „ ih l l l i lJll l i l S S S S S s s s s s s s s s S S S 2 2 S S 5 5 S S S E S IIIIIIIII irinuYfi o T O T tt) : ^  T CO o a Cu 1 ^ o o o o o o o —1 i i i i i i i i s 4 J k > 4 - > t . k i L a k f f c * U M o a 0 ,?| ^ ^ ^ j{ o o o o o o o o o * " S* S. S. . cn -4 n cn cn ** cr> n C» 4 t t •» s~ 3e «i «i n 4 1 « —t «> «• m rt <n — fc. —• —. ( i r t O cr> —« o ^ o o o © * * * * * — e o M^ <X>£-M^ C >cL>ckja.cuoaCCL LCM o o o o o o o o o o o o o o o o o o i r t « > « i > c » J i / i « > r - r t C B ooori«s«c>*f>*«n«w rtfN4«Nt«N4C»*C««*'*«»>«*** o o o o o o o o o I SS S <N1 rt CM *•«• 215 I s S ta 1*1 o o «: o OM U d c o o i i -i i If i M i in <Z a s o * C M O u O O-o " 3 * TJ •V ©» > c o <n S ; i 3 o j • d x Id J T m : o : cc o o g g o — — — — o S S S S S s s s s s R r » R r i o o o o o c* JT j=" jf J" jf o o o o o o jC jC -c £ o o o o o o • J <Q a) * * * * •! •! B 2 2 c c c — tS o o o o o o s s s s s s ! i i I II OJ S r~ co o l o o o i o f t o o i o i i o ! d d d ! d J . d d t o j j o o o o CN*. o d d s s o o HI III o o o c • -O f l JJ o o y u M « c ZJ1 •a « J "j «n r> « C C C OOO OM Oa 0* lit to *J> O OWN o o d d S S o o o o o o | tz ^ ?f «l o I s S 0 —» 1 5 o o o o o o o o : o : <£ 2 1 6 I I o I?. o o S=8 i s 1 | S.. o o d d o o d d 2 .s T J • £ 3 T J * * •S 2 •V •> n c §• s o —• 32 •a «• 1I o o S* £» S S «-« «x o o o o d s s o o o 2 c *> > S 2 tr i n » •III <w i 0 C J jr r i s s i T J T J I c c s s »-Vt VI o o o o o o o o o S S S 0.30 1 0.20 1 0.20 1 -*! s s s s S S S s i o o o o **! 3.00 1 1.00 1 11.00 1 7.00 1 S.OO 1 2.00 1 i f 3.00 1.00 11.00 7.00 S.OO 2.00 s ! s" i ll JT JT JT jT JT JT JT j O O O O O Q Q I VI tyi M M v» Vk v» j .£ T J C S -•—• 3 3 §» s O — s *• * g. £ T J >a T J -O « l i s «s< - T J O > ~ S ~ •° £ S * o £ 8 -. 2 " ° JS t T " o o. J» b. C —• C " i o —. —• 3 T ) » . 1. t. O i O O O Z ' i : e : a : -rf ! 3 ! CP : e ; a « « . w *f a IIII III • O O O O O O O S SSI SI 2 2 2 S S | | S S S o o o o o o o o o o o . o o o l l l - I S J l i l i S i i i i i i § § ! t o o ! • ; — — N O C S . o d o d s —• O. I o «j • JC b> I O I 8 I z o o cu u cc i l l ! f - SI Ol \ H H H ce v 0 m Pi Q 3 K T I a n u o s 0> Z o 0 v A «l M z n o H x < H <0 0 U •4 •<' Q V) OS U co < H Z U bl u z 0 H H O D « H 01 Z O u o co D o g ! 3 c*»-— i 1 — "B *S B i - S u 2 1 X X X x x x X X X X X : x x x x ) : x x x x x x x x x x * X X X X X : X x x X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X » X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X O O O O O O O O O O O O O 1 , 0 0 ^ o o o r - 0 « ^ c » ^ c » c > - » - ^ w O r t C > ^ c ^ ^ i - ^ o » o o o o o 0 0 O O r - N O O O f * I O O O O O O O O O O O O O « t o o o o o o o o o o > O -v CO O > »00»»«*«Or tO» i r r X X X X X X X x x x x x x x x x x x x x x - x x x x x X I X X X X X X X X X X X X X X X X X X X X X : x x x X X X X X X X X X X X X X X X X X X x x x x X imiiliiHiililiillilllHiii««iiiiiiiiiiii M X X K M X M M M K M K M K M 218 ! ^ 1 u ta i 0 « a ; •a • 1 i 1 | i 5 s : > . ! w t; ! ^ - -S : > * « i « -S > • » 5 5 i • 2 a 1 1 : 1 1 1 1 1 i * i l l > > „ ; 2 i -5 i T ^ s i : s 5 I o 2 —• • o o X t ONS SITE 1 1 1 X X • 1 § a ~ a i 1 1 • i CONDI 1 x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x j i P O ! - | S.-& o o o o o o o o o o o o o o o o o o « o o o o o o o o o ; - . o - o - a o o o o o o o j ; ~ c > < 3 o s o o j • o. ! g | a C 3 0 0 o o o o o o e » o o o o o o o o r > « r . o o « » o o o o « » - ^ 0 20 « » 0 0 0 0 0 0 ^ C > S " ' S < > ' " 2 0 < > ! i E „ i », 1 i I 1 X X X X x x x x x . x x x X X « • ' x X | X x X X X X X X X X X X X X X x x x x x x x x x x x x x x x x x ; • > 1 o i cs « «/» i 2 , x x X X • T 5 - -S < o ^5 x X X X X X X X X X X X X X ; « « X K X X X X X X X X X X X X X X X X X X X X X X X X X X X X j ! ^ 219 APPENDIX 3 Daily site work force report. 223 224 227 j i a I o • u 1 111 1 1 Traffic 1 1 Contrl.l 1 1 1 m : 1 o o o o o o o o o o s s ; ! *a X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X • | 3 g * : E ~ x ! | ' """ ^ 3 * ! ae X X X X X X X X X X X X X X I x X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X t : -"sss >- >- i — — >. x >~ x >• »~ » >- >- X >- » -~ ° ~ - j c i C/> -4 Code Ttado 1 1 O 1 t9 1 C 1 O I f 2 1 O C 1 : O 0 ' e» i c: i S S ! 11 !l X U O rt 1 p o & d c Hg I fi 'c * x *J « i C —< T J «J Q (3 1 £ 2 i < 2 £ < 5 ! « M «W *rt U> r- (9 I O O O O O 1 C» 1 C 1 1 ! 5* Si X O rt 1 M b -4 o>rt 1 p O —« C «} 1 n a i : s : g -< o 9 ci j -v u> <— t» { O O O O 1 c s s ! III! *f S i § 5 S " 8 « p o »» —« «a i o C -« -a u a i x o • B «j • i M E H P S ^ A U 1 O O O O O 1 c •1 o •> o 1 1 - I i X O O rt 1 £ «£ s #3 #» tS 1 N v in w r- O i O O O O O 1 n o • o 11 I! =••5, s i - I l l «*l P © c*» rt a "« I g S | 3 | s i £ «E 5 (3 n iS i CM ^ <n *» r- (9 1 o o O O O 1 hi < rt O 1 —* U 1 = 5 i a S% S ! « p o & a *« ! 5 S S I I S i O O O O O 1 s tft o •I o If 1 g £ 1 3 I rt X O O rt J « p a & rt c «e i 3 C rt -a « a c i K3 £ <S § cS w 3 ] o o o o o o e ! M o • * o « 1 0 g-a s : S-SK »a i M O O & rt i & & £ § £ ' . S o 5 o o * fel 1 § i i • ! O 1 S ! 8 j O 1 I M i O 1 I 8 ] 2 ! 8 | 1 i | 228 — — ii _ * "a. M § ! -« « x x x x x x x XI 1 I X 1 1.00 I | X 1 1.00 I | XI 1 I XI 1 I XI 1 1 XI 1 I XI 1 I X 1 1.00 1 | X 1 1.00 1 | XI 1 1 XI 1 I XI 1 I XI 1 I s > 1 M 1 1 1 1 \ 1 1 OO'l 1 t 1 OO'l 1 i t 1 1 1.00 | | 1 1.00 1 | =• i E i i 1 - = i o< — — — _ w • I • •35 : -— «y» »— • J x x j X X X X X ! ; > — > - > - > — > - » - > - . ! X X X X X X X >-*>-»— J— J— J ~ JV-X X X X X X X < >~ fc. 1- H I X X X X X X » • f » • « . I . k . X X xxx x ! «—»-»—>—»—>— ! X X X X X X X X X X » - IM fx Jx tw 1 X X X X X X X X X X X X X X O |M 1, 1. >, >. V . [ X X X X X X »—»••• J— I Suptr- ( (Jc) 1 1 1 1 111 IN U> W ^ f l (M M .) JJJ 4"» «-H «"» t>» rt 1 - - - - - - 1 H i n n H n rt i j N m n n n N H rt O -» •o ! •a «-• 1 • o t o J « * e 1 o • O ! £ • a Is i ° • I A • tn o i * ° ! It I !( J i ' S • —• -»* v a -H • oi 4»> m M> «— o J o o o o o o a m o * o If 1: —f .M u o —J •t; ** *- J* 2><-« | i - a f S 5 = £ £ i 121 ,s S O O O O O U ©» t c < •» O 1 • O i P I! -H x u e —• o S o o o o ** m o • o 11* i S££SsS 3 0 0 0 0 ° DO ! a i s i i —« *4 1 HI •S - -3 I _ " ** kVt (M ^ rt .4 £ I I s 3 5 4M) V t/« U> O w> o • o -4 M H p - I l l s l i l ls &S3S3 rt «n- *n to o •» o <* o If I 0 p O 0»rt O "3 *n *•> i— O a ST * • M IH i l l M IM M 1 DATE | jl | jj 3 j i-i 1 1 IM 8 229 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
https://iiif.library.ubc.ca/presentation/dsp.831.1-0063989/manifest

Comment

Related Items