search for




 

Switching properties of multivariate Shewhart control charts
Journal of the Korean Data & Information Science Society 2017;28:911-25
Published online July 31, 2017
© 2017 Korean Data & Information Science Society.

Bo-Jung Kim1 · Gyo-Young Cho2

12Department of Statistics, Kyungpook National University
Correspondence to: Gyo-Young Cho
Professor, Department of Statistics, Kyungpook National University, Daegu 41566, Korea. E-mail: gycho@knu.ac.kr
Received June 8, 2017; Revised June 30, 2017; Accepted July 5, 2017.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
We investigate the properties of multivariate Shewart control charts with VSI pro- cedure for monitoring simultaneous monitoring mean vector and covariance matrix in term of ANSW (average number of switches), probability of switch and ASI (average sampling interval), ATS (average time to signal). From examining the ANSW values, we know that it does not switch frequently. The VSI control charts are superior to the corresponding FSI control charts in terms of ATS. And, it can be also seen that the VSI procedures have substantially fewer switches for small or moderate shifts of the mean vector and variances.
Keywords : Average number of switches, average run length, average sampling interval, average time to signal, switching property