供應商代管存貨(Vendor Managed Inventory ; VMI)存貨政策爲現階段學術界視爲重 點之存貨政策，然而並非所有供應商均能負擔VMI存貨政策之龐大設置成本，由於供 應商與零售商雙方均不願意支付额外成本之負擔，寧願採取保守的訂購策略，因此造成 缺貨情形普遍存在且難以降低。本研究主要討論供應商與零售商在尋求整體供應鏈最大 利潤之目的下，依據利潤成長幅度訂定傳統存貨模式與VMI存貨模式之最佳轉換點。 本研究主要探討數量折扣對供應商利潤減少的影響，改採VMI存貨模式後可將該減少 利潤回收。利用供應商與零售商二階之供應鏈銷售模式，建構單位時間内個別與整體總 利潤之表示式，進行模式分析，進而求得單位期間内總利潤。最後依據本研究所建構出 之單位時間利潤表示式模式，驗證之結果，得到利潤成長與VMI設置成本回收最適的轉換式。

VMI (Vendor Managed Inventory) is the key points of Nowadays inventory management policies that multitudinous experts are discussing. However, not all vendors can afford to pay the huge setup cost of Vendor Managed Inventory. Because of the vendors and retailers are unwilling to pay the extra costs, they would rather take the traditional inventory management policy for save money. So, the shortage cost will hard to reduce. When tracing the maximum of benefit in supply chain, this research investigates that the best switch point evaluation that according to the increasing rate of the profit. The research use the two-stage inventory model with vendors and retailers in supply chain to developed the formula for each vendor's profit. The model basis for two situations, holding retailer's profit and profit increase from quantity discount. A research found the better switch point evaluation formula of traditional inventory management polimanagement policy. For setup cost of VMI can be retrieved by the increasing rate of the profit in few phases.