UBC Theses and Dissertations
Truck routing and scheduling for wood chip transportation to a pulp mill using Simulated Annealing Nadimi, Fattane
Optimization and improvement techniques have been employed to improve truck transportation in the forest industry. Most studies in this area focus on log transportation and there is not much literature available on wood chip transportation which is distinct from log transportation in several ways : chip-truck transportation usually considers a longer planning period, requires a more complex driver scheduling, involves strict limitations on truck unloading capacity, and considers service priorities for major suppliers. The objective of this thesis is to model and improve truck transportation of wood chips to a pulp mill. To achieve this, a network that transports wood chips from a number of sawmills to a pulp mill with limited truck unloading capacity was studied and an optimization model was developed to consider wood chip production plan at supplier sawmills, transportation of wood chips and unloading at the pulp mill. A simulated annealing metaheuristic was adapted to solve the model and the results for a case study in British Columbia are presented. The results of the metaheuristic showed that the total penalties for truck waiting times could be reduced by 7 percent ($31,000) compared to solutions obtained through simulation. The results also suggested that the fleet size could be reduced by one-third of the actual fleet size used by the pulp mill. In order to explore the impact of various structural parameters on the transportation network, sensitivity and scenario analyses were used to study the impacts of fleet size, an additional truck dumper, truck types, and switch point locations for truck drivers. The results indicated that the pulp mill could reduce its fleet size and an additional truck dumper could reduce transportation costs. The study also suggested that half of the fleet should be replaced by self-unloading trucks and the investigation of the switch point locations for drivers indicated that the existing switch points were the best available options. The simulated annealing model could assist the pulp mill truck dispatchers to achieve better transportation plans. The scenario and sensitivity analysis could help the pulp mill manager to adapt the most profitable changes in the structure of the transportation network.
Item Citations and Data
Attribution-NonCommercial-NoDerivs 2.5 Canada