Application of multi-criterative decision making approachesin automotive spare parts management

In spare part management, to make a selection among the alternative suppliers, we have to decide assessment criteria, importance of criteria and understanding the performance of suppliers against the criteria. Accordingly, supplier selection becomes a problem of multi criteria decision making (MCDM). In the application division of the thesis an original product manufacturer's supplier selection process is examined. The first step of the process is determining the criteria that the company's three experts have to make the assessment against three criteria. Jointly defined criteria are; cost, quality, reliability, flexibility are then detailed to sub criteria. The aim of doing this is to gain sensitivity and precision to the process. Right after this determination comes the assessment of the performance of the suppliers. Then the process goes on to apply the Methods. Orderly TOPSIS, AHP, Fuzzy TOPSIS, and Fuzzy TOPSIS are the used Methods. After obtaining the outcomes of the Methods new step is to make the sensitivity analysis. In MCDM problems sensitivity analysis can be made via several ways. A way is to change the importance level of criteria. In many cases change of importance weights of criteria change the ranking of the suppliers. The major contribution of this thesis is to reveal and provide details and crux to the original product manufacturer's to better manage their spare part management process, to rationalize this process and to show how to select the right method and contribute to its right usage.