運用限制理論對原料存貨管理改善之研究-以橡膠發泡業A公司為例

The use of Theory of Constraints on the raw material inventory management improvement: Rubber foam industry, Company A, for example

蔡宗洺(Tsung-Ming Tsai)

指導教授 ： 李文瑞

崑山科技大學/商業管理學院/企業管理研究所/碩士(2012年)

摘要

本研究運用Goldratt 博士所提出的限制理論 （Theory of Constraints，TOC），倡導需求拉動運作模式的理念，應用於個案公司之庫存管理改善。本研究以限制理論為基礎，將本研究的個案公司之供應鏈運作模式，由傳統的推式改為需求拉動運作模式，並以個案公司之庫存歷史數據資料來進行試算，評估運用限制理論改善個案公司庫存管理的可行性，使能有效因應高度需求不確定性之市場環境，以需求拉動運作模式與動態緩衝調整，避免不準確的需求預測導致庫存控制失靈。 本研究透過個案公司歷史資料的試算驗證，分別設定廿五項試算條件，除了以當週用量作為下單量參考，另加入動態緩衝調整之試算條件設計進行分析比較，得出結論除了以當週用量作為下單量之外，另外加上動態緩衝調整。當庫存水準位於緩衝上限以上時立即就當週用量減少緩衝上限以上之差額;若庫存水準位於緩衝下限以下時則不必急於調整下單量，先觀察四週後再就當週用量增加緩衝下限以下之差額進行下單。 本研究證明了個案公司在面臨需求異常波動時，提出之有效的改善方法與調整對策，能使個案公司之庫存水準能快速因應市場的需求變動，降低存貨與成本控管壓力，提升個案公司之彈性應變能力。

關鍵字

庫存管理 ； 限制理論 ； 拉式需求 ； 變動需求

並列摘要

This study applies the Theory of Constraints, proposed by Dr. Goldratt, in the raw materials management of a company. It promotes the concept of pull-based supply chain and applies to improve the stock management of individual company. This study, based on Theory of Constraints, changes the supply chain from the traditional one, “push-based” to the “pull-based” one, which is demand-driven. Then, according to the historical stock data of case company, the study calculates and evaluates the possibility of Theory of Constraints to see if it could improve the stock management. The results shows it could effectively meet the high demand of uncertain market. In order to avoid the inaccurate demand forecast which may cause the stock out of control, the company has to use the pull-based mode and adjust the dynamic buffering.
By the historical data of the case company, this study sets up twenty-five conditions for trial tests. Apart from using the weekly demand as the reference of order quantity, it adjusts the dynamic buffering as well. When the stock level exceeds the maximum limit, it would decrease the demand of that week in order to balance the odds immediately. On the other hand, if the stock level is under the minimum limit, it would not adjust the order quantity. It orders only based on the demand of that week to balance the odds after four-week observation.
This study proves that when the case company facing the unusual fluctuation, the stock level could meet the market demand rapidly if the company proposes the effective improvement and adjustments. It also could release the pressure of stock and cost control and improve the ability to work resourcefully.

並列關鍵字

Inventory management ； Theory of constraints ； Pull-demand ； Flutuaction in demand

參考文獻

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sharing in a vendor managed inventory partnership, Journal of Business