UBC Theses and Dissertations

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UBC Theses and Dissertations

Decision analysis models for aircraft engine maintenance planning using discrete event simulation Razavi, Behnam


With stringent standards for materials, manufacturing, operation, and quality control, jet engines in use on commercial aircraft are very reliable. It is not uncommon for engines to operate for thousands of hours before being scheduled for inspection, service or repair. However, due to required maintenance and unexpected failures aircraft must be periodically grounded and their engines attended to. The tasks of maintenance and repair without optimal planning can be costly and result in prolonged maintenance times, reduced availability and possible flight delays. These factors have a negative impact on both the airline operators and the passengers alike. Aircraft manufacturers and maintainers, who provide after sale services, see significant benefits in constantly improving health management and maintenance practices by deploying the most effective maintenance strategies. Maintenance is seen as an imposed cost that ought to be minimized. Airlines must evaluate new technologies and their possible role in reducing the long term expenditure for operating a fleet of aircraft throughout its life cycle. A significant share of these expenses goes towards maintenance of these aircraft, especially their engines. This study presents a model-based integrated decision making system for aircraft engine maintenance planning. The goal is to determine the optimum number of engines on an aircraft for maintenance based on logged engine operation data in order to maximize the use of estimated remaining time to the next service as well as to minimize the duration of downtime. To achieve this, engine condition is used in a set of preliminary Discrete Event Simulation (DES) models to evaluate and provide the most effective maintenance policies for the aircraft engines. To assess options for making decisions, a comprehensive model is developed based on the integration of the smaller preliminary maintenance models for one, two, three and four engine maintenance cases. Results from these analyses determine the optimal number of engines tagged for maintenance on any aircraft in the fleet that arrives at the service facility. Since the materials, technicians and other costs are proprietary information, this study is time-based but allowance is made for the user to include associated costs and thus perform cost-based decision making.

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Attribution-NonCommercial-NoDerivs 2.5 Canada