Multi-Objective Mathematical Model for Supplier Selection and Order Allocation under Multi-Item Condition

Suppliers play an important role in reducing costs and increasing product quality. Accordingly, assessment and selection of suppliers based on desired criteria, has become one of the fundamental headquarters of decision-making in supply chain management. Since now the suppliers have a significant impact on the success or failure of a company, purchases that previously was considered as a mere tactical tool, now is known as a strategic task. So, considering the importance of the subject, the aim of this study is providing a fuzzy approach in order to select multi-product and multi-purpose supplier and determine the economic order quantity in supply chain. Objectives considered in the above model include minimizing the total cost (including the purchase cost, cost of returned goods, control and order costs), maximizing quality (including the product’s quality and services provided by suppliers, and maximizing the amount of products received from suppliers on-time. To resolve the above issue, the Lp-Metric and Zimmermann fuzzy approach -due to dealing with uncertainty and getting more flexibility of decision-making- are applied. The results represent the best suppliers to purchase the products from and also optimized allocation to each of them.