Multi-Objective Optimization of Inventory Replenishment Problem for Distribution Centers by Considering Lead-Time and Capacity Constraints

In the big industries, the volume of commodities that used in a production cycle is capital-intensive. Therefore, the inventory management would be important especially in determining the capacity of warehouses, managing costs and responding to transportation concerns. It will be more considerable in the area of replenishment planning for distribution centers and even selling shelves. The main objective of this paper is to provide a multi-objective replenishment model by considering lead-time for the orders as well as obtaining the optimal numbers of replenishments and the quantities of orders. This model designed for the make-to-order inventory replenishment system by using a distributor. Confining the total numbers of replenishments as well as minimizing inventory costs is the two defined objectives. The inputs of the model are delivery limitations of suppliers and capacity constraint of distributor's warehouse. The model solved by standard multi-objective methods in discrete and continuous space. Then the two sensitivity analyses performed on the "numbers of replenishments" and "ratio of holding and back-order cost". The results show that the total cost of system would be raise upon increasing numbers of replenishments. Also After a specific value for the number of replenishments, the total cost would have significant jump because of enforcing to do unnecessary replenishments.