On the single item multi-supplier system with variable lead-time, price-quantity discount, and resource constraints

In this paper, we propose a mixed integer approach for solving a single item multi-supplier problem with variable lead-time, price-quantity discount, and resource constraints. This problem is important in the field of inventory control. However, to the best of the authors' knowledge, no work has been done for the problem. The proposed method not only can easily determine the optimal order quantity from multi-supplier system with different price-quantity discount policies, but also allows resource constraints to be added by inventory decision-maker as deemed appropriate in real-world situations.