A modified particle swarm optimization for solving the integrated location and inventory control problems in a two-echelon supply chain network

In this study, the design of a two-echelon distribution supply chain network for the seasonal products with multiple vendors (manufacturers) and buyers (retailers), and a set of warehouses for each vendor are considered. the locations of the buyers are known and the capacity of the warehouses is restricted while the buyers purchase different products from the vendors under all unit discount policy. the main objective of this research is to find out the optimal locations of the potential vendors in addition to the quantity ordered (allocation) by the buyers so that the total inventory cost including ordering (transportation), holding and the purchasing costs is minimized. besides, the distance from the buyers to the vendors is considered as the euclidean distance. the total budget to buy the products is limited and the production capacity of each vendor is also restricted. to solve the problem, a modified particle swarm optimization (mpso) algorithm is applied where the results are validated using a genetic algorithm (ga). finally, some computational examples are generated to assess the algorithms’ performance where mpso shows a better efficiency in comparison with the ga.