| 摘要: | 在傳統的經濟訂購量模型中，通常假設在銷售過程中相關的存貨參數是固定不變的，如商品的每單位購買成本、需求量、訂貨成本或持有成本等；然而在現今激烈的競爭市場中，有許多理由會使得供應商會透過降價活動來刺激零售商的買氣。當供應商提供了較低優惠價格時，零售商通常會採購較平常多的訂購量，待日後賣出後賺取差額的利潤，但因大量訂貨的結果也導致訂貨成本及存貨持有成本的增加。另外，在經濟訂購量模型中通常有一假設是值得討論的：收到所訂購的商品品質皆良好無瑕疵。事實上，所訂購的商品若在生產製造、運輸過程中有不可抗拒的情況產生時，將會有部分瑕疵品在所訂購的商品中。除此之外，商品變質、揮發等現象我們稱為退化現象，有些商品具有立即退化性現象，例如牛奶、蔬菜水果與魚蝦等。而部分商品會在一段時間內保持原先的狀態，並不會立即變質，稱為非立即退化現象，例如藥品過期變質、軟片變質與電子元件效用退化等。本文主要研究目的是以上述的各種因素為考慮基礎，針對傳統經濟訂購量模型中的條件加以改良及修正，以提供零售商做最適的訂貨策略。
本論文的研究架構如下：第一章為緒論，包含研究動機與目的、相關文獻探討和本論文研究架構。第二章探討瑕疵商品在瞬間價格折扣下零售商最適的訂貨策略。第三章延續第二章的概念，探討退化性商品在有限時間限制下存貨參數變動的最適訂貨模型。第四章探討非立即退化性商品在貨幣現值因素下的最適訂貨模型。第五章為結論，包含主要研究結果及未來研究方向。
The traditional EOQ inventory model assumes that the inventory parameters (for example: per unit cost, demand rate, ordering cost or holding cost) are constant during the sale period. In real life, there are many reasons for a supplier to offer temporary reduction in selling price to buyers. The buyer generally responds to the price discount by placing a special order for a large lot. But it may increase the holding cost and ordering cost. Further, the assumption of all items are perfect in each ordered lot is not pertinent. Because of defective production or other factors, there may be a percentage of imperfect quantity in received items. Besides, deterioration is defined as decay, change, spoilage or obsolescence that results in decreasing usefulness from its original purpose. But some items are not deteriorated as soon as they received by the retailer. In the fresh product time, the product has no deterioration and keeps their original quality. This phenomenon is named as non-instantaneous deterioration. According to the above reasons, we extend traditional EOQ inventory models and propose improved models that can provide optimal decision-making to retailers.
The thesis is consisted of five chapters. In chapter 1, it covers the motivation and objectives of this research. We also survey the related literature and provide a research framework. In Chapter 2, we explore the optimal ordering policy for economic order quantity with imperfective items under a temporary price discount. In Chapter 3, we propose a finite time horizon inventory model for deteriorating items with cost changes. In Chapter 4, we present a partial backlogging inventory model for non-Instantaneous deteriorating items with stock-dependent consumption rate. In this dissertation, we develop some theorems to find the optimal ordering policies and provide numerical examples to illustrate the theorems we proposed. Finally, Chapter 5 provides the conclusions of this research and topics for further research. |
