Shewhart、CUSUM與EWMA計數值管制圖之品質偵測能力比較研究

A comparative study on Shewhart, CUSUM and EWMA attribute control charts

林宜蓉(Yi-Rong Lin)

指導教授 ： 黃允成

國立屏東科技大學/管理學院/工業管理系所/碩士(2014年)

https://doi.org/10.6346/NPUST.2014.00120

摘要

根據以往研究指出，當製程產生大偏移時，Shewhart管制圖之偵測效果較敏銳，但對現今產品設計以高品質為目標而言，大偏移之監測能力已不足以滿足需求，故當製程有微量變異時，應使用 EWMA管制圖或CUSUM管制圖來監測製程。當製程品質水準在管制範圍內時，此時希望 越大越好；反之，當製程品質水準在管制範圍外時，則希望 越小越好。故本研究將探討Shewhart管制圖、CUSUM管制圖與EWMA管制圖分別在不同的品質特性下，何者管制圖之偵測績效較佳。最後，本文提出7點具體結論供後續研究及實務應用上參考。

關鍵字

Shewhart管制圖 ； CUSUM管制圖 ； EWMA管制圖 ； 平均連串長度(ARL)

並列摘要

Based on literature review, when the process has a large offsets, Shewhart control chart's detect effects will better than the others. But for today's high-quality products requirement, the detect ability for large offsets has been insufficient to meet the demand. Therefore, when the process has a small offsets, EWMA control chart or CUSUM control chart should be used to monitor the process. When the process is in-control, the average run length is hoped the bigger the better. On the contrary, when the process is out-control, the average run length is hoped the smaller the better. In this paper, we will explore and compare the detecting performance among the Shewhart, CUSUM and EWMA control charts under a variant of quality characteristics. Finally, seven conclusions are drawn for future studies and practical applications.

並列關鍵字

Shewhart control chart ； CUSUM control chart ； EWMA control chart ； Average run length(ARL)

參考文獻

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Brook, D., Evans, D. A., (1972), “An Approach to the Probability Distribution of Cusum Run Length”, Biometrika Trust, 59(3), 539-549.

Chen, C. W., (2012), “Using geometric Poisson exponentially weighted moving average control schemes in a compound Poisson production environment”, Computers & Industrial Engineering, 63, 374-381.

Friedman, D. J., AT&T Bell Labs., Murray Hill, NJ, USA., Albin, S. L., (1991), “Clustered defects in IC fabrication: impact on process control charts”, IEEE Transactions on Semiconductor Manufacturing, 4(1), 36-42.