在本文中，我們主要著重於研究及比較各種製程變異數的管制圖，特別是在以下三種情況：監控製程變異數增加、監控製程變異數減少及同時監控製程變異數增加及減少。雙邊的 Shewhart 管制圖，我們利用不同的方法選擇其管制界限並比較其表現。關於 EWMA 管制圖，我們比較以樣本變異數取自然對數為監控統計量的管制圖以及利用樣本變異數的機率積分轉換當作監控統計量的管制圖。另外，我們也比較只單純使用上述統計量當做監控統計量、先對統計量做歸零動作再取 EWMA 及先對統計量做 EWMA 再做歸零動作的管制圖。另一方面，我們對 H-NEWMA (黃俊榕(2009)) 管制圖的管制界限做一些修正，並將其與其它管制圖做比較。最後我們以一個實際例子來說明所建議管制圖的實際應用。

Acosta-Mejia, C. A., Pignatiello, J. J. Jr. and Rao, B. V. (1999). “A Comparison of Control Charting Procedures for Monitoring Process Dispersion”. IIE Transactions 31, pp. 569-579.

Box, G. E. P. (1954). “Some Theorems on Quadratic Forms Applied in the Study of Analysis of Variance Problems: Effect on Inequality of Variance in One-Way Classification”. Annals of Mathematical Statistics 25, pp. 290–302.

Box, G. E. P., Hunter, W., and Hunter J. (1978). Statistics for Experiments. John Wiley & Sons, New York, NY.

Chang, T. C. and Gan, F. F. (1995). “A Cumulative Sum Control Chart for Monitoring Process Variance”. Journal of Quality Technology 27, pp. 109–119.

Crowder, S. V. and Hamilton, M. (1992). “Average Run Lengths of EWMA Controls for Monitoring a Process Standard Deviation”. Journal of Quality Technology 24, pp. 44-50.

Domangue, R., Patch, S. C. (1991). “Some omnibus exponentially weighted moving average statistical process monitoring schemes”. Technometrics 33, pp. 299–313.

Lawless, J. F. (2003). Statistical Models and Methods for Lifetime Data (2nd ed.), John Wiley & Sons, New York, NY.

MacGregor, J. F. and Harris, T. J. (1993). “The ExponentiallyWeighted Moving Variance”. Journal of Quality Technology 25, pp. 106-118.

Mongomery, D. C. (2009). Introduction to Statistical Quality Control (6th ed.), John Wiley & Sons, New York, NY.

NG, C. H. and Case, K. E. (1989). “Development and Evaluation of Control Charts Using Exponentially Weighted Moving Averages”. Journal of Quality Technology 21, pp. 242-250.

Page, E. S. (1954). “Continuous Inspection Schemes”. Biometrics 41, pp. 100-114.

Quesenberry, C. P. (1995). “On Properties of Q Charts Variables”. Journal of Quality Technology 27, pp. 184-203.

Roberts, S. W. (1959). “Control Chart Tests Based on Geometric Moving Averages”. Technometrics 1, pp. 239-250.

Shu, L. and Jiang, W. (2008). “A NEW EWMA Chart for Monitoring Process Dispersion”. Journal of Quality Technology, pp. 319–331.

Tate R.F. and Klett G.W. (1959). “Optimal confidence intervals forth variance of a normal distribution”. Journal of the American Statistical Association 54, pp.674-682.

Wortham, A. W. and Ringer, L. J. (1971). “Control via Exponential Smoothing”. The Logistics Review 7, pp. 33-40.

黃俊榕（2009）。利用EWMA管制圖監控製程變異數。碩士論文，國立清華大學統計研究所，新竹市。