個案公司為電子連接器專業設計製造廠，客戶群涵蓋筆記型電腦、手機、LCD TV等各類型消費型電子的台系、韓系與美系等國際代工大廠，其所生產的筆記型電腦電源連接器全球市占率約50%，是公司的主要獲利產品。2009年，個案公司生產全新開發的焊線式電源連接器，在客戶端發生斷電問題，所影響為整台電腦無法使用，該公司面臨每月320萬元的品質損失及客戶威脅轉單的重大危機，公司高層立即介入並成立六標準差專案改善團隊，積極尋求改善。本研究以此為主題，說明個案公司利用六標準差DMAIC的架構成功改善焊線式電源連接器的斷電問題，除了節省了每月320萬元的品質成本，更以優異的品質為公司增加了每月1500萬元訂單。
專案小組先以CTQ tree展開對應客戶需求的關鍵品質特性，進而找到可衡量的主要流程輸出變數，透過計量型、計數型與不可重複型的量測系統分析，確認進行研究所量測數據為可信，並檢討原有製程能力。在分析階段找出需要改進的流程輸入變數，透過製程改善將客訴不良率由1433dppm降低到564dppm，並進一步利用防呆設計，將客訴不良率再降到68dppm，滿足了客戶需求，使專案獲得成功。而以防呆設計觀念發展出來的「低壓注塑成型工法」初期良率不佳，專案小組利用「田口方法」找出最佳參數組合，成功提升良率，導入量產。最後，專案小組提出在產品開發階段就導入DFSS的建議，從先期就明確認知客戶需求以進行產品設計與驗證，方能降低在量產階段的品質損失。

The case company is a professional connector supplier, proving design and manufacture of connectors to world famous ODM in Taiwan, Mainland China, Korea, United States and etc. These ODM produces consumer electronics products like note book, mobile phone, camera, LCD TV, and so forth. Power jack connector is the breadwinning product of S company, which owns over 50% world -wide market share of notebook. In 2009, a new-developed connector, power jack with wire, encountered malfunction problem, causing whole note book shut down. It was a crisis, 3.2 million NT dollars of quality lost per month, customer threatened cancelling the order. Top management had immediately joined the crisis control and led a Six Sigma team to work out the solution. This thesis introduces the process of the case company using DMAIC approach to improve the malfunction of wired power jack connector. In this case, not only 3.2 million NT dollars quality lost per month was saved, but also gained extra 15million NT dollars order per month.
The Six Sigma team initially utilized CTQ tree to determine the critical-to-quality characteristics based on customer’s requirements, hence found the measurable main process output variables accordingly. Consequently, performing Measurement System Analysis to make sure that the data obtained in the case study was convinced, and reviewed existed process capability. Through methodology analysis, main process input factors were determined and improved, the defect rate was reduced from 1433 dppm to 564dppm (dppm represents defect part per million). Further ahead, poke-yokes were applied and lowered the defect rate to 68dppm, customer was satisfied. Herein, the fool proof “low pressure molding technique” applying on the wired power jack connector got poor yield rate in the beginning, the Six Sigma team adopted Taguchi methods to work out the optimal molding parameter combination, successfully promote the yield rate to 99% and above.
Finally, the Six Sigma team recommended the case company to launch DFSS approach in the beginning of product development. Designing customer’s requirements into products in early development stage so that quality lost will be saved.

1. 蘇朝墩，2009，六標準差，前程文化事業有限公司
2. 蘇朝墩，2006，品質工程，中華民國品質學會
3. 丁惠民譯，2006，精實六標準差工具手冊，美商麥格羅．希爾國際股份有限公司
4. 吳嘉晟，鄭大興，2004，製造業六標準差應用手冊，新文京開發出版有限公司
5. C.-T. Su, 2006, handout, TQM, National Tsinghua University, Taiwan
6. C.-T. Su, C.-J. Chou, and L.-F. Chen, 2009, “ Application of Six Sigma Methodology to Optimize the Performance of the Inter-Metal Dielectric Process,” IEEE Transactions on Semiconductor Manufacturing, vol. 22, no. 2, pp. 297-304
7. R.C. Law, Li Zhang, H.Y. Beh, J. Kmetec, Frank Wall, C.E. Chan and H.K. Koay, 2008, “ Six Sigma Methodology in Improving Assembly Yield of High-Power and High-Brightness Light-Emitting Diodes Packages for Automotive Application,” 33rd International Electronics Manufacturing Technology Conference.
8. Tarek Safwat, Aziz Ezzat, 2008, “Applying Six Sigma Techniques in Plastic Injection Molding Industry,” Proceedings of the 2008 IEEE IEEM, pp. 2041-2045
9. T. Bendell, 2004, “ Managing Engineering Improvement by Six Sigma,” International Engineering Management Conference, pp. 1114-1116