A re-evaluation of repetitive sampling techniques in statistical process monitoring

ABSTRACT

In this article, we review the literature on the use of the repetitive sampling technique with quality control charts. We raise some important concerns and questions regarding its application and underlying assumptions. We show that a fixed sample size method that requires on average the same amount of sampling can be designed to have as good or better statistical properties when monitoring with data that are normally distributed. Repetitive sampling methods can be useful, however, when monitoring with count data.

KEYWORDS:

• Average run length
• average sample number
• EWMA chart
• probability of signaling
• Shewhart chart
• statistical process control

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/16843703.2023.2246770

Notes

1. For the design parameters provided by Nawaz et al. (2021) in Table 1, λ = 0.4 is repeated three times. This was a typographical error as the first one is λ = 0.2 and the second one is λ = 0.3.

Additional information

Notes on contributors

Nesma A. Saleh

Nesma A. Saleh is an Associate Professor of Statistics at the Department of Statistics, Faculty of Economics and Political Science, Cairo University. She holds her B.Sc. (2009), M.Sc. (2012), and PhD (2016) in statistics from Cairo University. Her main area of interest is statistical quality control.

Mahmoud A. Mahmoud

Mahmoud A. Mahmoud is Dean of the Faculty of Economics and Political Science, Cairo University. Prior to becoming Dean, he was the Vice Dean for Education and Students’ Affairs, and a Professor of Statistics at Cairo University, Faculty of Economics and Political Science. He holds his BS (1992) and MS (1997) in statistics from Cairo University, and PhD (2004) in statistics from Virginia Tech – USA. His primary area of interest is statistical quality control and improvement. He is a member of the Editorial Board of Quality and Reliability Engineering International, and Review of Economics and Political Science (REPS). He is a Deputy Editor-in-Chief in Journal of Humanities and Applied Social Sciences (JHASS).

William H. Woodall

William H. Woodall is an Emeritus Professor in the Department of Statistics at Virginia Tech. He is a former editor of the Journal of Quality Technology (2001–2003). He is the recipient of the Box Medal (2012), Shewhart Medal (2002), Hunter Award (2019), Youden Prize (1995, 2003), Brumbaugh Award (2000, 2006), Bisgaard Award (2012), Nelson Award (2014), Ott Foundation Award (1987), and best paper award for the IIE Transactions on Quality and Reliability Engineering (1997). He is a Fellow of the American Statistical Association, a Fellow of the American Society for Quality, and an elected member of the International Statistical Institute.