A COMPARISON OF PHASE I CONTROL CHARTS

Authors

  • Margarethe Coelho University of Pretoria
  • Subhabrata Chakraborti University of Alabama
  • Marien Alet Graham University of Pretoria

DOI:

https://doi.org/10.7166/26-2-1026

Keywords:

Retrospective phase, nonparametric, simulation

Abstract

A carefully done Phase I analysis is a vital part of an overall statistical process control and monitoring regime. Distribution-free control charts can play a useful role in this analysis, as a parametric model assumption often cannot be adequately verified. The performance of two distribution-free charts for the location – the mean-rank and the median chart – are compared in this paper. For benchmarking reasons, the parametric -chart is included in the comparisons. It is seen that the distribution-free charts are in-control robust, whereas the -chart is not, and they both perform similarly to the -chart for normally distributed data. However, for non-normal data, they both outperform the -chart. The results provide evidence in favour of using distribution-free Phase I charts in practice. Concluding remarks and suggestions for future research are given.

Author Biography

Marien Alet Graham, University of Pretoria

Department of Statistics, Lecturer

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Published

2015-08-03

How to Cite

Coelho, M., Chakraborti, S., & Graham, M. A. (2015). A COMPARISON OF PHASE I CONTROL CHARTS. The South African Journal of Industrial Engineering, 26(2), 178–190. https://doi.org/10.7166/26-2-1026

Issue

Section

Case Studies