在半導體設備產業中，最關鍵的是能夠在客戶提出維修需求時能維持一定服務水準內，使其得以修復停機的機器而降低失去產能的損失。為防止停機損失的狀況，通常其解決辦法是備存備件以直接替換的方式修復，但如果備存所有可能會損壞的備件，其成本將十分高昂，甚至相當於整台設備。因此，備存零備件便成為設備商的一個主要問題，即決定多少數量應在每個區域來支援客戶達到其所需之時間內的服務水準並仍能降低庫存成本。
零備件物流問題的徵結在於低隨機需求、高備件成本、目標時間內服務水準和各區域倉庫存貨共用或從水平緊急轉運來有效地利用存貨。而本研究主旨即從目前已公開的文獻中尋找適當的模型為個案公司解決其存在已久的全球零備件庫存水準的問題。經過模型推導，本研究結果在個案公司中不僅維持客戶所要求的服務水準及大大減低各區域倉庫零備件安全庫存量外，同時也建構出各區域倉庫間相互協同之物流網絡及精省各區域倉庫之庫存成本。

In semiconductor equipment industry, it is important to have machine down repaired within customer required time-based service level to lower any cost because of machine down case. For preventing from the lost, the general solution of equipment provider usually would be to have backup spares for replacement in time, but it costs high if they backup all spares. Therefore, it becomes a major issue to decide how many quantities should stock in each region to support customer required time-based service level in considerable cost reduction.
Features of service parts logistics problem are very low random demand, high part cost, target time-based service levels, and inventory sharing or ELTs to utilize inventory across multiple stocking locations. In this study, we are looking for a suitable model for the case company in current published literature globally, and implement it in the case company to solve their inventory problem. The result shows that not only higher time-based service level in the case company and lower inventory level (means lower cost) but also build up a collaborated network between regional warehouse and save inventory holding cost for each regional warehouse.

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