| 摘要註: |
精實管理強調的是速度，核心價值是降低庫存和縮短前置時間，精實管理為拉式生產管理系統，精實精神就是豐田管理系統之核心價值-持續改善，但是精實管理實踐問題在於沒有明確步驟不容易有效實踐。而六標準差強調可透過統計工具達成控制變異、改善變異、管理變異…等讓產品產出、品質、流程…等得到控制或改善，其優點在於有明確方法架構容易實踐，但在資訊產品快速轉變的資訊產業界中實施時，經常發生在產品改善還沒達到4.5標準差時產品就已經退出市場，所以反而因為產品市場的快速變化與時間變異造成整體改善效益受到質疑，且因為過於強調財務效益，也會產生專案導入過於重視短中期效益，而非長期效益。 1998年奇異公司總裁傑克•威爾許(Jack Welch)提出將精實管理與六標準差結合為精實六標準差的構想。後有學者George (2002)指出，當六標準差無法大幅改善流程速度時，可藉由精實六標準差 (Lean Six Sigma,LSS) 來達成，也就是提出把 LSS 的方法與工具應用在流程設計改造階段。本研究針對F公司之內部交易流程再造案例，探討並實踐精實六標準差的應用，研究的方法係採用精實六標準差之DMADV【定義( Define)、衡量(Measure)、分析(Analyze)、設計(Design)、驗證(Verify)】的程序結合蔡明修(1999) 提出之流程再造(Business Process Reengineering，BPR)四步驟：流程重現、流程轉換、流程評估與流程設計來重新設計內部交易流程。 本研究案例從兩項關鍵指標統計結果發現：一、改善前原內部交易流程作業時間是120分鐘，流程週期效率是21%，改善後流程作業時間下降到60分鐘，流程週期效率提升到50%，二、庫存金額從平均每月新台幣7.6億元下降到約新台幣5億元，庫存金額減少34.2%。這兩項關鍵指標的統計結果驗證了精實六標準差之DMADV可以顯著改善內交流程；除此之外，其他效益還包括有：作業總前置時間由560分鐘進步到120分鐘，流程速度提升4.6倍，整體前置時間減少78.6%、改善後作業步驟由13個步驟減少成5個步驟，作業步驟減少61.5%、物停滯時間由400分鐘遞減為60分鐘，減少86%、文件作業時間由120分鐘減少為60分鐘，縮短50%等，這些指標結論皆顯示精實六標準差應用於內部交易流程再造確實有效。因此，期望藉此研究方法架構能提供給強調垂直整合之電子製造服務(Electronics Manufacturing Services, EMS)廠做為內部交易流程再造之參考。 The core value of "lean management" is to reduce the inventory and shorten lead time - the key point is "speed". Lean management is a "pulling" production management system. The spirit of lean is the core value of Toyota management -- continuous improvement. However, the shortfall of lean management is lack of well-defined procedures and not easy to implement. On the other aspect, "Six-Sigma" emphasizes on controlling, improving, and managing variation of production output, quality and flow by adopting statistics methods. The advantage of six-sigma is clear structure, easy to implement. Nevertheless, in the rapid changing information industry, it’s not unusual that a product has quitted from the market before its production process has reached 4.5 sigma capability. Therefore, the overall benefit of six sigma improvement is always questionable due to rapid change of the product market; and because of its emphasis on the financial benefit, it sometimes overly focuses on the short and mid-term benefit instead of the long-term benefit when a project is implemented. In 1998, Welch (CEO of GE) proposed the concept to integrate “lean management” and “six-sigma” to be lean six-sigma (LSS). Later, a scholar George (2002) indicated in his book “Design of LSS” that if the flow speed can not be improved a lot by six-sigma, which can be achieved by LSS. It means the method and tools of LSS can be applied to the stage of “design and improvement”. The research selects the F company as the case study that applies the LSS for the process reengineering of intra-company sales. Method adopted in the study is the DMADV (Define-Measure-Analyze-Design-Verify, DMADV) model structure of LSS accompanying with the four steps of BPR (Business Process Reengineering) that proposed by Tsai Ming-Xiu (1999): flow reproducing, flow switch, process evaluation, and flow design to redesign the intra-company sales. Results, from two key indicators, show that the benefits of applying LSS in the intra-company sales are as follows: First, the total operation time of the entire process was reduced from 120 to 60 minutes and the process cycle efficiency was increased from 21% to 50%. Second, the monthly amount of the inventory for intra-company sales was decreased from NTD 760 million to about NTD 500 million, a 34.2% down. The result of the two key indicators statistic show the DMADV of lean six-sigma can significantly improve the process of intra-company sales. In addition, other benefits include: the lead time was reduced from 560 minutes to 120 minutes, a 4.6 times raise in process speed and a 78.6% decrease in lead time; the operating steps were reduced from 13 steps to 5 steps, a 61.5% reduction; material stagnation period was decreased from 400 minutes to 60 minutes, a 86% reduction; paperwork time was reduced from 120 to 60 minutes, a 50% reduction. All of the indicators show that applying lean six-sigma in the process reengineering of intra-company sales is effective. Thus, hopefully the research method framework can provide to the Electronics Manufacturing Services (EMS) company that emphasizes the vertical integration as the reference for the process reengineering of intra-company sales. |