運用六標準差與實驗設計建立製程最佳化-以降低C公司鋼板裁剪平坦度變異為例

Applying Six Sigma and Design of Experiment Methodologies in Process Optimization –A case Study on Reducing Smoothness Variation in Steel Cutting Process at C Company.

李建成(Chien-Cheng Lee)

指導教授 ： 陳啟政

國立屏東科技大學/管理學院/企業管理系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00130

摘要

自1990年六標準差（Six Sigma）在品質改進方面成效卓著，並逐漸受到高度肯定，近年來再次為品管界所重視且蔚為風潮。它是一種以數據推動的問題解決方法，邏輯化整合許多品質管理的工具，運用六標準差之基本步驟：定義、量測、分析、改進、控制(DMAIC)方法不僅可從產品面作品質的控管亦可在事務面作流程簡化，讓企業迅速提昇品質與競爭力。
實驗設計法可應用於追踪整個實驗進行過程，在實驗過程中，應先決定好產品的品質特性，並初步建立現行製程參數與水準的設定，然後，根據直交表產生的數據進行實驗並收集實驗後的數據。隨後再使用變異數分析的計算結果，來建立製程參數以獲得製造最佳化。實驗設計是能有效的解決問題的工具，它可以改善產品的性能、製造流程、設計和系統，是節省實驗時間和成本的利器。
本個案研究運用個案公司品質專案改善團隊及品管手法將顧客聲音轉換成關鍵品質；並運用六標準差品質改善方法之定義、衡量、分析、改善、控制五大流程管理步驟與實驗設計（DOE）法中直交表及變異數分析來找出造成鋼材經分條機與矯平機裁剪輥軋後其平坦度變異的關鍵要因與最適製程條件組合後；再進一步評估試行成效，以決定管制方式來維持產品穩定品質。
運用適合於組織文化的分析工具才能由流程切入消除過程變異及快速建立以客戶為尊的核心流程，如此才能降低成本、提高效率並維持顧客的忠誠度。

關鍵字

六標準差 ； 顧客聲音 ； 關鍵品質 ； DMAIC ； 品質改善團隊 ； 實驗設計 ； 流程變異

並列摘要

The six sigma program has received great attention for its huge success in improving quality since 1990. As a data oriented approach, the six-sigma program logically combines many managerial tools. Following the Define, Measure, Analyze, Improve and Control (DMAIC) procedures approach to reconstruct manufacturing processes to improve quality assurance management competitive ability, companies that implemented six-sigma have demonstrated that they can drastically improve their quality in record time.
The Design of Experiment (DOE) method was applied to track the experimental progress. During the experimental process, product quality characteristics are determined and processing parameters and levels were initially set. Based on an adequate orthogonal array, the experiments were conducted and data collected. Afterward, ANOVA was calculated to complete manufactured quality optimization.
The Design of Experiments (DOE) technique is the most efficient problem-solving tool for improving product, process, design and system performance with a significant reduction in experimental time and cost.
A case study using a quality improvement team and quality control tools transforms the voice of customers into critical quality attributes. The Six Sigma DMIAC procedure and DOE improvement methods, including orthogonal arrays and ANOVA were applied to metal slitting and roll leveling processes to obtain critical smoothness through process optimization. The execution of effective evaluation with decision control types maintains robust quality.
Applying suitable organization culture analysis tools may eliminate variations and establish quick response to core customer demands. The result is reduced cost, increased efficiency and the maintenance customer fidelity.

並列關鍵字

Six-Sigma ； VOC ； CTQ ； DMAIC ； QIT ； DOE ； Variation

參考文獻

23.鄭榮郎，（2005），「精實六標準差推行之架構」，品質月刊，第41卷，第12期，第58-60頁。

30.蘇朝墩，（2008），「六標準差執行上的三個思維：策略、戰術與文化」，品質月刊，第44卷，第10期37-44頁。

9. 吳復強，(2004)，「多重品質特性之穩健設計最佳化方法」，元智大學工業工程與管理研究所博士論文。

27.葉純愿，（2005），「品質改善團隊採用知識管理機制對團隊績效之影響」，元智大學企業管理研究所碩士論文。

Between Cultural and Technical Change“, John Wiley & Sons, Inc.