A direct procedure for monitoring the coefficient of variation using a variable sample size scheme. Issue 6 (3rd July 2017)

• Record Type: Journal Article
• Authors: Yeong, Wai Chung; Khoo, Michael B. C.; Lim, Sok Li; Lee, Ming Ha
• Is Part Of: Communications in statistics. Volume 46:Issue 6(2017)
• Page Start: 4210
• Page End: 4225
• Publication Date: 2017-07-03
• Subjects: Average number of observations to signal -- Average run length -- Average sample size -- Coefficient of variation -- Variable sample size; Primary 90B25 -- Secondary 62P30; Mathematical statistics -- Periodicals; Mathematical statistics -- Data processing -- Periodicals; Digital computer simulation -- Periodicals; 519.5
• DOI: 10.1080/03610918.2015.1109659
• Languages: English
• ISSNs: 0361-0918

Abstract

ABSTRACT: A variable sample size (VSS) scheme directly monitoring the coefficient of variation (CV), instead of monitoring the transformed statistics, is proposed. Optimal chart parameters are computed based on two criteria: (i) minimizing the out-of-control ARL (ARL1 ) and (ii) minimizing the out-of-control ASS (ASS1 ). Then the performances are compared between these two criteria. The advantages of the proposed chart over the VSS chart based on the transformed statistics in the existing literature are: the former (i) provides an easier alternative as no transformation is involved and (ii) requires less number of observations to detect a shift when ASS1 is minimized.