An Evolutionary Algorithm for Supplier Order Allocation with Fuzzy Parameters Considering Linear and Volume Discount


1 IE Department, University of Tafresh, Tafresh, Iran

2 IE Department, College of engineering, University of Tehran, Tehran, Iran

3 IE Department, University of Tafresh, Tafresh, Iran‎


In this research, supplier order allocation problem is investigated. The problem is that one buyer wants to allocate required products to pre-selected suppliers. Allocation is considered under some constraints such as capacity, delivery rate, linear discount and volume discount. Objectives of the model are maximizing the total value of purchase, minimizing the total cost of purchase and minimizing the total number of defective products purchased. We propose a Multi-Objective Mixed Integer Non-Linear (MOMINL) model, for multi-period suppliers order allocation, in situation where suppliers offer discount. In practice, some information such as buyer demand and suppliers delivery rate is uncertain, so fuzzy sets are applied for handling uncertainty. Since PSO and GA are one of the most effective methods to find a good solution to a difficult Multi-Objective Problem (MOP), a multi-objective optimization algorithm based on PSO and GA (MOPSOGA) is developed to solve the model and give a set of Pareto optimal solutions. The efficiency of the Pareto Archive obtained from the algorithm is evaluated based on spacing and diversity metrics.