應用精實六標準差建立TFT-LCD組立製程庫存管理機制

Abstract

為了降低營運成本及接近下游工廠減少運費的考量，面板廠已開始進行全球化的佈局，轉移到勞工成本低且有顧客需求的地方生產，不過，模組廠的數量增加後，可能會受限於生產良率變化、材料短缺的轉單效應及客戶特殊需求等因素，造成面板組立製程成品(以下簡稱Cell)無法即時去化而出現呆滯的情形，若多個模組廠都發生類似的情形，Cell的庫存控管難度就會增加，特別是Cell約佔面板總成本的40%，有必要針對Cell庫存進行管理。本研究希望透過精實六標準差(Lean Six Sigma)的應用，並以國內一家面板廠為例，進行個案的研究與實證分析。研究結果顯示，透過精實六標準差的DMAIC手法可以幫助企業在最短時間內找到影響Cell庫存量的因子以及這些因子對Cell庫存的影響程度，再利用迴歸分析，得到一個相關度83.8%的公式，並採用腦力激盪與親和圖搭配使用的方式，針對這些關鍵因子予以結構化的解析，可成功改善Cell庫存天數，亦可做為日後面板廠新廠房的Cell庫存管理模式。

In order to reduce operating cost and transportation cost, panel manufacturer start to study global operations to move factories in low labor area or where is close to customers. However, more locations of backend module assembly factories, more difficult for panel manufacturer to control the cost of semi TFT-LCD product(i.e. cell). The factors cause idle material including yield rate, order transferring, customer’s special request. If the factors happened at the same time in different sites, it will be hardly to control cell inventory level which is almost 40% within total panel cost and very crucial for panel makers management. Taking one of Taiwan’s panel makers as example, this report is the case study through the application of LSS (Lean Six Sigma). The result of this study shows that through DMAIC of LSS, the subject can find out each factor and its influence ratio to cell inventory in short time. Moreover, by using regression analysis, we can conclude with a formula which is 83.8% positive related to cell stock. And then subject analyze factors’ structure through brainstorming and affinity diagram. This can improve cell stock level, and become new sites’ call stock management mode thereafter.