Integrate Historical Demand of EWMA and TOC Replenishment Policy to Improve Inventory Performance in Semiconductor Manufacturing

• Main Author: 項彥華
• Other Authors: 張永佳
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/53949751521209273148

碩士 === 國立交通大學 === 工業工程與管理學系 === 100 === Inventory management is an important indicator of the running performance of a factory. Theory of Constraints, or TOC, proposed using Demand-Pull and Buffer Management to manage supply chain inventory, and many researches have shown it to be effective. However, within the context of products with long replenishment lead time and high demand variance, TOC is likely to fail to respond quickly, resulting excessive stock or shortage. This thesis develops a new replenishment strategy, combining TOC with exponentially-weighted moving average (EWMA) of history demand and custom inventory adjustment rules. Unlike TOC, replenishment lead time will decide the weight of EWMA and the timing of target inventory level adjustment. Trends of demand can be spotted by examining the EWMA value, managers can then move accordingly. To test the generality of the method this research proposed, we simulate different scenarios, and apply it on the history data of a real product made by a local IC fabrication plant. The results show that our method works well on products with long replenishment lead time and high demand variance.