在一般的商業交易行為中，我們發現到零售商基於增加市場佔有率及降低未來需求的估計誤差
等原因會提供消費者預購的價格折扣。此外，以往文獻通常假設需求率是一固定的常數。然而由產
品的生命週期看來，需求只有在穩定期才唯一常數，通常是與時間有關。當需求對時間具有敏感性
時，零售商如何決定物品的預購折扣率和訂購策略使其總利潤有最大值是值得探討的課題。
本計畫擬將建立一個退化性產品在需求隨時間變動需求及允許信用交易下，當零售商提供預購
價格折扣優惠時，如何決定最適的預購折扣率及訂購策略，使其利潤極大化。我們將以嚴謹的數學
方式證明所推得的預購折扣率及訂購策略不僅唯一而且為全域最佳，並以數學分析所得到的性質建
立演算法。最後，我們將舉例說明並提出結論。
In business dealing, there exists many factors like advance booking discount to make retailers
buy goods early. For companies, the advance booking discount strategy is common and useful in
reality to decrease the estimation error in demand and to increase the market share. Furthermore,
in real life, the demand is usually influenced by time. In the growth stage of a product life cycle,
the demand rate can be well approximated by a linear form or exponential form.
In this project, a deterministic inventory model for deteriorating items with time-varying
demand and advance booking discounts is developed. In addition, we allow for two-echelon trade
credits. We then try to provide a simple solution procedure for finding the maximum total profit.
Finally, numerical examples will be used to illustrate the results.
