Modified Group Runs Control Charts to Detect Increases in Fraction Non Conforming and Shifts in the Process Mean

摘要

In this article, we propose 'Modified Group Runs' (MGR) charts useful to identify increases in fraction non conforming and to detect shifts in the process mean. It is verified that the MGR charts significantly reduces out of control 'Average Time to Signal' (ATS) as compared to most of the well-known control charts. The attribute control charts considered for comparison are the Run Length CUSUM chart (Bourke, 1991), Bernoulli CUSUM chart (Reynolds and Stoumbos, 1999), synthetic chart (Wu et al, 2001), and GR chart (Gadre and Rattihalli, 2004b). The variable control charts considered for comparison are X chart, synthetic chart and GR chart (Gadre and Rattihalli, 2004a).