本文探討分散供應鏈問題，其中某製造商供應二種可替代產品與某零售商，而此零售商在一個銷售量與存貨量相關的市場內，同時考慮產品替代性及存貨量需求刺激的效應下，銷售此二種產品。為了達到與集中供應鏈相同效果，此製造商擬定合約保障與此零售商，包括提供相較於分散供應鏈便宜的零售價及接受所有未售完產品的退貨政策。本文之目的乃同時藉由此二種產品訂貨量之決定、此二種產品零售價及退貨價格之協商來協調此供應鏈並創造雙贏的局面。因此，我們為此二產品分別找到零售價範圍及退貨價格範圍供雙方協商以便達到Pareto-efficiency。

This study addresses a decentralized supply chain whereby a manufacturer supplies two substitutable items to a retailer who sells the two items in a stock-level dependent demand market, considering the effects of product substitution and inventory demand stimulation. To operate the chain as a centralized supply chain, the manufacturer engages in a contractual commitment that not only offers the two cheaper wholesale prices but also accepts all unsold products at the end of the selling period. The objective is to coordinate the chain and create a win-win situation by means of jointly determining the two optimal order quantities, negotiating the two wholesale prices and setting the two buyback prices. To this end, a range of the two wholesale prices and a range of the two buyback prices to ensure the contract Pareto-efficiency are presented. Many managerial insights regarding the product substitution and the inventory demand stimulation are observed thereafter.