Modeling and Solving of Multi-Product Inventory Lot-Sizing with Supplier Selection under Quantity Discounts

摘要

This paper proposes a multi-product and multi-period inventory lot-sizing problem with supplier selection under vehicle capacity and both all-units and incremental quantity discounts. In addition, we consider that buyer's limited storage capacity. The objectives are to minimize total costs, where the costs include purchase cost of the products, ordering cost for the suppliers, transportation cost for the suppliers and holding cost of the remaining inventory in each period. It is assumed that demand of multi-product is known over a planning horizon. The problem is formulated as a mixed integer linear programming (MILP) model. Finally, a numerical example is provided to illustrate the solution procedure. The results, the buyer needs to determine what products to order in what quantities with which suppliers in which periods, in order to satisfy overall demand and minimize the total costs.