On the Performance of Control Charts for Simultaneous Monitoring of Location and Dispersion Parameters

• Published in: Quality and reliability engineering international Vol. 33; no. 1; pp. 37 - 56
• Main Authors: Zaman, Babar, Riaz, Muhammad, Lee, Muhammad Hisyam
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01-02-2017
• Subjects: assignable causes; average run length; Charts; Control charts; Cumulative sum charts; CUSUM; Dispersion; EWMA; location; Monitoring; Parameters; Proposals; simultaneous monitoring
• ISSN: 0748-8017; 1099-1638
• DOI: 10.1002/qre.1989

A single control chart is very famous to control assignable causes that shift the process because of variations in parameters (e.g., location and dispersion). Simultaneous monitoring of processes is another popular approach used for the bilateral processes. In this study, we have proposed the mixed control charts for simultaneously monitoring of process location and dispersion parameters. We have used the idea of mixed exponential weighted moving average and cumulative sum charts and designed the charting structures for simultaneous monitoring. The proposals are compared with several existing counterparts. The comparisons reveal numerous advantages of the proposed charts over the other existing scheme. The practical application of the proposed charts is also highlighted using an illustrative example based on a real dataset. Copyright © 2016 John Wiley & Sons, Ltd.