Determining the Optimal capacity of warehouse using queuing models and fuzzy prioritization techniques

Warehouses، as one of the key elements of supply chain systems، play critical role in establishing the logical relationship between suppliers and customers. There are many different methods for warehouse management in companies، that the well-known method، is the simultaneous use of private and public warehouses. The purpose of this article is to develop a queuing theory-based model for determining the optimal capacity of private warehouse in order to minimize the total costs. At first، the warehouse and its associated supply chain are modeled using the queuing theory. Then، a cost function model related to the construction of private warehouse in different sizes is introduced considering the time value of money. As the values of some mentioned cost are unknown and a definite estimation of their values cannot be reached، a triangular fuzzy number for each cost parameter is assigned، based on experts opinion to overcome the related uncertainty. As the values of cost function for different capacities of warehouses are fuzzy numbers، a fuzzy prioritization method is proposed for the prioritizing different capacities and choosing the best capacity for constructing a private warehouse. The results of numerical examples confirm that unlike the previous approaches which are applicable for certain conditions، the proposed model could be easily and efficiently appropriate for various environments and conditions.