A Robust Bivariate Control Chart Alternative to the Hotelling's T2 Control Chart

• Published in: Quality and reliability engineering international Vol. 30; no. 1; pp. 25 - 35
• Main Authors: Abu-Shawiesh, Moustafa Omar Ahmed, Golam Kibria, B. M., George, Florence
• Format: Journal Article
• Language: English
• Published: Bognor Regis Blackwell Publishing Ltd 01-02-2014; Wiley Subscription Services, Inc
• Subjects: bivariate control chart; Hotelling's T2 statistic; masking effect; outliers; robust estimation; simulation study; statistical process control
• ISSN: 0748-8017; 1099-1638
• DOI: 10.1002/qre.1474

In this paper, we proposed a new bivariate control chart denoted by TMEDMAD2 based on the robust estimation as an alternative to the Hotelling's T2 control chart. The location vector and the variance‐covariance matrix for the new control chart are obtained using the sample median, the median absolute deviation from the sample median, and the comedian estimator. The performance of the proposed method in detecting outliers is evaluated and compared with the Hotelling's T2 method using a Monte‐Carlo simulation study. A numerical example is considered to illustrate the application of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.