應用六標準差降低庫存-以W公司為例

Six Sigma Application for Inventory Reduction – A Case Study of W Company

嚴瑞吉(Yen, Jui Chi)

指導教授 ： 陳建良

國立清華大學/工學院/工業工程與工程管理學系碩士在職專班/碩士(2017年)

摘要

綜觀今日，在競爭激烈的市場環境壓力下，內有來自客戶對需求服務的前置時間不斷縮短，外有市場需求能見度不明的疑慮。所以在此全球競爭市場的製造觀念中，存貨雖被視為必要的資產，但高存貨水準意味著資金積壓及競爭力的流失。因此，如何追求適切的供應鏈存貨管理的低成本與高效率，已成為企業必須不斷追求的重要目標之一。
本研究係以推動六標準差改善活動極具成效的個案公司為實證研究對象，個案公司之產品應用於智慧型手機之觸控面板，因該產業之需求變化頻繁與極端，造成該公司在存貨管理上面臨了問題庫存。因此，個案公司以降低問題庫存為目標成立六標準差專案，應用六標準差（Six Sigma）之改善流程DMAIC (Define、Measure、Analyze、Improve、Control) 進行問題的改善。改善專案中利用統計方法加以分析，試圖找出重要之影響因子，最後籍由改善其關鍵因子更改庫存管理流程，以降低問題庫存的產生，並監控指標的改善成效，進而提升企業內部競爭能力。
本個案在不影響客戶服務水準下所獲得效益包含問題庫存比例由原本的14.9%降至6%以及報廢比例由原本的5.2%降至0.9%，整體成本節省約九十萬美金之多，讓個案公司因而提升生產力及競爭力。此外，此專案的進行讓相關部門人員更瞭解流程中各環節所需要的投入與產出的關係，不僅強化團隊意識，也使六標準差深植於企業文化中，促使企業不斷精進，以達成企業永續經營的最終目標。

關鍵字

六標準差 ； 庫存管理 ； 光學膠

並列摘要

Nowadays, under highly intensive market competitive pressures, enterprises inside are continuously facing clients’ needs to shorten the lead-time; enterprises outside are confusing the ambiguous market needs. Thus, in the manufacturing conception of global competitive market, although inventory is viewed as essential assets, overstock still implies accumulation of assets and the loss competitiveness. How to balance the supply chain inventory management between low costs and high efficiency has become one of important goals for enterprises.
The present study is to show the experience of W company which has successfully and effectively implemented Six Sigma application to reduce excess inventory. Therefore, in order to decrease the problem inventory, the W company launched a Six Sigma project by use of the improvement procedure of Six Sigma ─Define, Measure, Analyze, Improve, and Control (DMAIC)─ to reduce the bullwhip effect from internal process. This project used statistical methods to seek for the vital influential factors. Finally, the company improved the disconnected processes so as to decrease excess inventory and further to enhance the company’s internal competitiveness.
The W company without influencing client service level obtained the benefits including the decrease of problem inventory rate from 14.9% to 6% and the scrap rate from 5.2% to 0.9%. The overall costs saved about $0.9 million US dollars and made the company further enhance productivity and competitiveness. In addition, due to the Six Sigma project executed, the relevant department members can understand more about the process involved of the relationship between input and output. It not only strengthens teamwork consciousness, but deeply integrates Six Sigma into the enterprise culture and further achieves enterprise’s ultimate goal of continuous improvement and sustainable operation.

並列關鍵字

Six Sigma ； Inventory Management ； Optical Clear Adhesive

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