Abstract
Nowadays, selecting the best suppliers has strategic importance in this competitive environment for companies. Supplier selection consists of both qualitative and quantitative criteria, so it is considered as a multi-criteria decision-making (MCDM) problem. There are many investigations about supplier selection and many publications have been issued since now, but they have not separated qualitative and quantitative criteria for evaluating suppliers and allocating orders. Hence, we propose an integrated model that evaluates suppliers and allocates order to them. In the first step, we evaluate suppliers by qualitative criteria such as financial structure, services and loyalty with Fuzzy analytical hierarchy process (FAHP) and gain their weights. Meantime, the fuzzy logic and triangular fuzzy numbers are utilized to handle ambiguity of human judge. In the second step, for evaluating suppliers and allocating orders with quantitative criteria such as cost, defect rate, and delay considering company's demands and suppliers' limitations a multi objective linear programming (MOLP) is formulated. This model consists of four objective functions: minimizing defect, delay, and costs. For influencing the suppliers' weights which are achieved from qualitative evaluation by FAHP, an objective function is defined to maximize the overall weights of suppliers. A case study is applied to illustrate the stages of Supplier selection, evaluation and order allocation.