To increase sales and reduce default risks, a supplier may offer its retailers either: 1) a cash discount; 2) a fixed credit period M if the order quantity is greater than or equal to a predetermined quantity W. Likewise, a retailer in turn offers its customers a credit period N, which has a positive impact on its demand but a negative impact on its default risks. In this paper, we establish an inventory model for a retailer in a supply chain when a supplier offers either a cash discount or a delay payment linked to order quantity; meanwhile it offers its customers a permissible delay in payments. Then, we derive several theoretical results to determine the optimal solution under various situations and develop an algorithm to solve this complex inventory problem. Finally, several numerical examples are given to illustrate the theoretical results and provide some managerial insights.
European Journal of Industrial Engineering 7(3), pp.370-392