Monitoring the Multivariate Coefficient of Variation using Run Rules Type Control Charts
Abstract
In practice, there are processes where the in-control mean and standard deviation of a quality characteristic is not stable. In such cases, the coefficient of variation (CV) is a more appropriate measure for assessing process stability. In this paper, we consider the statistical design of Run Rules based control charts for monitoring the CV of multivariate data. A Markov chain approach is used to evaluate the statistical performance of the proposed charts. The computational results show that the Run Rules based charts outperform significantly the standard Shewhart control chart. Moreover, by choosing an appropriate scheme, the Run Rules based charts perform better than the Rum Sum control chart for monitoring the multivariate CV. An example in a spring manufacturing process is given to illustrate the implementation of the proposed charts.
Keywords
Cite
@article{arxiv.2001.00996,
title = {Monitoring the Multivariate Coefficient of Variation using Run Rules Type Control Charts},
author = {P. H. Tran and A. C. Rakitzis and H. D. Nguyen and Q. T. Nguyen and K. P. Tran and C. Heuchenne},
journal= {arXiv preprint arXiv:2001.00996},
year = {2020}
}
Comments
27 pages, 4 figures, 12 tables