- 學位論文
探討造成存貨誤差之原因—以TFT-LCD產業為主
Study The Reasons for The Inventory Inaccuracy—Using TFT-LCD Industry As a Example
摘要
本研究中，以台灣TFT-LCD之中小型面板製造產業為個案研究重點，因為產業製造時程為30至45天，甚至可能長達60天，卻使得原物料變成產品，交付至訂單客戶手中，需經過從原料供應商供貨、製造至出貨，其中經過的時間遠遠大於訂單下單至交貨的時間。而多數製造者共通的應變方式有二，一為提高原物料的庫存量，二則是提高市場需求預測來進行製造，但這些方式的缺點，均造成企業現金資本的積壓，降低企業流通資金的週轉率，導致投入資本與營業收入不成正比。也因此，如何降低原物料的庫存成本、在製品的持有成本，相對於企業製造技術的提高更顯重要，但這些多屬於概略的思考模式。 本研究鎖定的TFT-LCD製造產業，其製造流程分為三大部分：第一階段(Array)為「玻璃基板」的基礎處理；第二階段(Cell)，進行「玻璃基板」與「彩色濾光片」處理與合併；第三階段(Module)為客製化規格模組組裝與成品包裝。 本研究採取個案研究的方式，探討存貨誤差的原因，並針對此些原因成立與否進行評估，其原因的產生，一方面為由業者提出目前於企業中已產出之顯性原因，另一方面由本研究者透過對該企業營運流程的了解及理論學習的應用，提出假設性原因，根據事件史分析中所提出判定原因具有之風險率、殘存函數及各原因的概似函數分析，提出明確、可靠的導因，並視各原因為單一獨立事件，單一評估該原因可靠度，針對過去已被認定之成因予以評估、分析，以推翻原有誤認之原因或支持新假設原因的成立，利用最後提出信度較高之造成存貨誤差的原因，再與業者討論提出可適行之改善方案。
並列摘要
In this research, we use the medium-and-small-sized manufacturer of TFT-LCD panels in Taiwan as our case studies. Because it takes 30 to 45 day even 60 days for the process making the “Raw Material” become “Products” for delivery. In such process, it is necessary to pass through the course from the supply of “Raw Material Supplier”, the production of “Manufacturing Dept.” to shipment. Therefore, it takes much more time than the course from order-making to delivery. Most of manufacturers have two following response methods: One is to increase the inventory of “Raw Material” and the other is to raise the market demand forecast for production, however, both of which will cause the backlog of corporate cash capitals and reduce the turnover rate of corporate working capitals, resulting in indirect proportion of invested capitals to operating incomes. Therefore, how to reduce the holding cost of “Raw Material” and the carrying cost of “WIP (Work in Process)” is more important than how to enhance the manufacturing technology. This research targets at the TFT-LCD industry, which process can be divided into three following parts: For the Array, it is a fundamental processing of “Glass Substrate”; For the Cell, we process and combine “TFT Array Substrate” and “CF (Color Filter)” to turn into “cells”; For the Module, it is the module assembly with a customized specification and the packing of finished goods. With “Case Research”, we study the reason for the inventory inaccuracy and also evaluate if such reason is existed. For the formation of such reasons, one is a visible reason that is provided by the vendor and also has been existed in their businesses. The other is a hypothetical reason that is provided by the researcher through his/her understanding of such corporate operation process and the application of theoretical learning. And based on the “Hazard Rate” and the “Survival Function” of “Event History Analysis” for reason determination this research makes the evaluation and the analysis to further provide a definite and reliable basis to reverse the presumed reason or to support the existence of new hypothesized reason. This research also makes use of the credible reason causing the inventory inaccuracy to discuss with the vendor and to provide an applicable improvement project.