運用CONWIP概念於半導體供應鏈多層級存貨監督機制

Semiconductor Supply Chain Monitoring Schemes for Echelon WIP Inventory Using CONWIP Concept

楊博鈞(Po-Chun Yang)

指導教授 ： 郭瑞祥

共同指導教授 ： 蔣明晃

國立臺灣大學/工學院/工業工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.01767

摘要

半導體產業本質上是結合高科技、高度資本密集的產業，整個產業處於激烈競爭與快速變遷環境中。半導體供應鏈具有高度垂直分工的特性，上下游不同的企業所追求的目標不一，導致整個供應鏈分割為許多片段，所以導致整體供應鏈之績效不佳，以及難以對整個供應鏈進行監控。因此，為滿足顧客準時交貨與相關服務水準之要求，半導體供應鏈中的各個成員必須有效的整合前端製程以及後端製程，以提昇顧客的滿意度與改善整體供應鏈的效率。
本研究主要運用供應鏈系統多層級存貨量(Echelon inventory)以及CONWIP系統的觀念於半導體供應鏈，以建構一半導體供應鏈監控機制。本研究首先依據服務水準目標與層級在製存貨(Echelon WIP inventory)之間的關係，並在考量生產系統之特性以及CONWIP系統之影響下，在給定服務水準目標的情形之下建構最小化供應鏈二層級在製存貨模型；接著再以遞迴求解以及提高內部層級的服務水準概念發展之演算法，並以二元搜尋法找尋適當的內部服務水準，將二層級的模式擴展至多層級，以得到多層級在製存貨上界。並利用求解模型所得到之各層級在製存貨上界作為監控指標，並經由模擬驗證本研究所設定的多層級在製存貨監督上界之有效性。經由模擬驗證的結果有下列結論：
(1)藉由本研究提出以遞迴求解以及提高內部服務水準概念發展之演算法，可有效得到多層級的在製存貨上界，其結果亦小於以階段觀點得到之整體在製存貨上界；
(2)相較於過去研究，本研究以層級在製存貨取代階段在製存貨作為監督上界，使整體供應鏈系統能夠在較低在製存貨量的情況下，得到較佳的服務水準。主要的原因系統中在製存貨配置之不同，以及利用整體的資訊來進行規劃所致。

關鍵字

半導體供應鏈 ； 多層級在製存貨 ； CONWIP

並列摘要

The semiconductor industry with its high capital investment and hi-tech nature faces fierce competition and quick environment changes. The semiconductor supply chain has a vertical disintegration character, and each member of supply chain pursues for different goals and this results in the poor performance of supply chain and the difficulty in monitoring it. Therefore, in order to enhance the service levels and improve the performance of the whole supply chain, it is essential for all members to share their information and synchronize their operations, i.e., there is a need to integrate the front-end and back-end in the semiconductor supply chain to meet customers’ on-time delivery requirement.
This research attempts to develop a semiconductor supply chain monitoring scheme based on the concepts of echelon WIP inventory and CONWIP system. The first step in the proposed scheme is to construct a two-echelon model which takes the features of the production system into consideration with the goal of minimizing the echelon WIP inventory control limits of the supply chain under the service level constraints. Next, the model is extended to a multi-echelon model through raising the service levels of the internal echelons and solving the model iteratively. The algorithm searches the proper internal service level with the concept of binary search. With the resulting echelon WIP inventory control limits from the model, the proposed monitoring scheme has been validated through simulation study.
Based on the simulation validation results, the conclusions are drawn as follows:
(1) By raising the service levels of internal echelons, the proposed scheme can effectively derive the multi-echelon WIP inventory limits, which is lower then the stage-based WIP inventory limits;
(2) Compared to the traditional stage-based inventory monitoring scheme, the proposed echelon-based monitoring scheme can obtain a higher service level under the lower inventory levels. This is the result of reallocating of the WIP limits and the utilizing of overall information.

並列關鍵字

Semiconductor Supply Chain ； Multi-Echelon WIP Inventory ； CONWIP

參考文獻

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