Early order commitment is one of the strategies for supply chain coordination, wherein a retailer commits to purchase a fixed-order quantity and delivery time from a supplier before the real delivery occurs. In this paper, an analytical model is developed for a supply chain with one supplier and multiple
retailers, where the manufacturer uses a wholesale price discount scheme based on retailers' early order commitment periods to induce the retailers to commitment their orders in advance. This model can be used to determine the optimal early commitment periods for the retailers, and to determine the optimal discount scheme for the supplier.