為鼓勵零售商訂購更多商品，供應商允許零售商在信用期間可以延遲付款。然而，整個銷售週期，價格調整是很正常的現象。因此，這篇研究在經濟訂購批量下考慮價格調整與信用交易。第一個模型為非瞬間退化商品之價格與需求率有關的探討。第二個模型延伸了第一個模型，當商品開始惡化時，考慮需求率與時間有關。兩個模型目的皆為決定信用交易下非瞬間退化商品的最佳銷售定價與訂購決策。我們從採購方面的最小成本化來決定補貨週期與從銷售方面的最大利潤化來決定銷售價格。特別的是考慮兩階段定價的策略，亦即在非惡化時期與惡化時期採取不同售價。經由數值例子與敏感度分析說明了求解過程以及探討主要參數在決策上的影響，研究更展現出兩階段定價優於一階段定價。

To encourage the retailer buy more products, the supplier often allows the retailers to postpone paying during the credit period. Also, price adjustment is common during sales period. This paper develops the economic order quantity models with price adjustment and trade credit considerations. First, a model for non-instantaneous deteriorating items with price-dependent demand is developed. The second model extends the first model to consider time-dependent demand when items start to deteriorate. For each model, the objective is to determine the optimal selling pricing and ordering policies for non-instantaneous deteriorating items under trade credit. The replenishment cycle time is determined to minimize the cost from the procurement perspective and the selling prices maximize the profit from the marketing perspective. Specially, we consider two-tiered pricing which the selling prices are different in the non-deteriorating and deteriorating periods. Through numerical examples and sensitivity analysis, we show the solution procedure and discuss the influences of major parameters. We also demonstrate that the two-tiered pricing is better than one-tiered pricing.

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