在信用期及允許缺貨下之賣方管理存貨再訂購點模型

A ROP-Based Vendor-Managed Inventory Model with Shortage Allowed under Credit Period

秦于婷(Yu-ting Chin)

指導教授 ： 沈國基

國立中央大學/管理學院/工業管理研究所/碩士(2007年)

摘要

在賣方管理存貨的文獻中，大部分在探討成員間成本關係和存貨水準，而且定價為固定。在一供應商和一零售商，供應單一產品給下游的環境下，使用再訂購點的連續盤存制模型，並加入信用期來更符合賣方管理存貨環境。本研究假設前置時間的需求和零售價有一線性關係並符合常態分配，且允許缺貨情形。
本研究合併Moon和Choi的連續盤存制下的缺貨模型和Shinn等由供應商訂定信用期模式，希望達到整個供應鏈利潤最大化。吾人證明其凹函數存在一最大利潤，並建立一演算法同時找出最佳訂購數量、再訂購點、成本加乘率。
吾人使用Matlab、Mathematica 5.2和Excel軟體為工具，以求出整個供應鏈利潤最大化和最佳訂購數量、再訂購點、成本加乘率的最佳解；並用於實驗分析和敏感度分析。透過這些分析可以了解服務水準越高缺貨發生數量呈遞減關係；在信用期模式下，我們發展一實驗來了解上下游利潤分享比例和信用期其相關性，可知呈線性關係，斜率為負，當上下游利潤分享比例越大時信用期就越小，也就是說上游利潤會提升，且下游利潤下降。

關鍵字

賣方管理存貨 ； 信用期 ； 資訊分享

並列摘要

In VMI related literature, the periodic review inventory control model was mostly used on supply chain member’s cost and inventory level. And the price is assumed exogenous determined. This research focuses on environment of a distribution channel that involves a single supplier who sells only item to a single retailer. Our approach is using the ROP-based model with credit period. Demand during the lead time is represented as a linear demand function of retail price which follows Normal distribution. And the lost-sale is also allowed.
This study incorporates the Moon and Choi’s continuous review inventory model with lost-sale and Shinn et al.’s credit period policy. Our objective is to maximize the supply chain annual net profit. We prove its concave function, and establish an algorithm procedure to find the optimal order quantity, reorder point, and markup ratio simultaneously.
We use Matlab、Mathematica 5.2、and Excel as tools to solve the optimal solution and have the experiment analyses and sensitivity analyses. Through these analyses, we discuss the higher service level along with the saving of shortage cost can be achieved by the efforts of investing in reducing shortage situation. After formulating the length of credit period problem in mathematical models, we show that the profit ratio and credit period is linear function. The slope is negative. And then the profit ratio is increasing in the supplier’s profit and decreasing in the retailer’s profit.

並列關鍵字

Vendor-managed inventory (VMI) ； Credit period ； I

參考文獻

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