Semiconductor Supply Chain Monitoring Schemes for Echelon WIP Inventory Using CONWIP Concept
Date Issued
2006
Date
2006
Author(s)
Yang, Po-Chun
DOI
zh-TW
Abstract
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.
Subjects
半導體供應鏈
多層級在製存貨
CONWIP
Semiconductor Supply Chain
Multi-Echelon WIP Inventory
Type
thesis