A hybrid solution approach with multiple criteria based decision-making method and simulation for spare part inventory problems in aviation industry

For companies carrying on businesses in aviation maintenance/repairment industry, management of spare part inventories and improvement of factory workflow process are very crucial goals. Multiple criteria based decision-making and simulation, as a couple of techniques of operational research are used integratedly for making these goals achieved in the implementation phase. For finding a solution for inventory problems of spare parts for aircrafts, it is essential to determine the priorities of the components, which are detached and taken to the factories, as well as the improvement of service lines. For these reasons, in this study, multiple criteria based decision-making approach with simulation was used for a solution to problems related to spare part troubles faced in aviation maintenance and repairment industry. With the implementation, it was aimed at determining priorities of the components waiting to be repaired, developing scenarios about increasing component productivity, utilization rates of sources and reducing the waiting-period on lines and elimination of the usage of unproductive capacity as well. Also, the outputs of different scenariosacquired by changing source quantities are aimed. In this study, to determine the priority order of the aircraft components for repairment, multiple criteria based decision-making techniques and simulation were applied and the holding track problem caused by the components waiting for maintenance was examined as well. In my thesis, my goal is to determine the maintenance priorities of the broken spare parts detached from aircrafts and waiting in holding tracks and to improve the process of factory's workflow with simulation. In the implementation, methods of multiple criteria-based decision-making, Queuing theory and simulation were wielded. Conducts of the system under the various circumstances were examined by simulating the model which belongs to process of factory workflow. And, their outputs were collected. In the implementation, VIKOR method was used in the phase of prioritization of the components and maintenance/repairment priorities of the components were determined. In accordance with the order of priority of VIKOR, model concerning to factory system was simulated with simulation and ARENA program was providing scenarios. In the last part of the study, the orders of precedence of the scenarios produced with simulation were obtained with PROMETHEE method. Also, the parameters of the criteria were obtained with ENTROPY method. As a result of the order of precedence, the most suitable scenario for the factory has been specified and various advices were presented to the company after the interpretation of acquired findings.