Paper Title
Supplier Selection Problem with Using Multi-Criteria Decision Making Methods: A Case Study in a Gas Mask Factory

Thisstudy aims to find a suitable supplier for buying an equipment which are very important and using to produce a gas mask. The company wants to work with only one supplier in 14 different alternative suppliers. The research provides a great help for selection of supplier to the company with prioritizingsome factors, and to find the most suitable supplier for the company.This case study is implemented in a gas mask factory in Turkey.Based on the literature review and interviews with experts, the main criteria are deduced asPrice, Quality & Safety, Delivery Time, Flexibility of Supplier, Performance History, Reputation in Industry and Technical Capability of the Firm.The problem is solved with using AHP and PROMETHEE methods. Analytic Hierarchy Process (AHP) method is used for weightingand PROMETHEE method is used for ordering all suppliers. The findings of the case study will reveal the preferences of company for supplier selection according to importance of criteria. Keywords: Multi-Criteria Decision Making, Supplier Selection, AHP, PROMETHEE.