Paper

Constructing SPC Charts by Cumulative Square and Cumulative Variance Methodologies


Authors:
Xia Pan; Jeffrey E. Jarrett
Abstract
The authors discuss the methodologies for constructing quality control charts by cumulative square and cumulative variance methodologies. These methodologies correspond to the EWMS and EWMV methods proposed by MacGregor and Harris (1993). Based on the distributions of the quality control chart statistics, we focus on the average (mean) cumulative square and average (mean) cumulative variance schemes to arrive at control limits appearing as parallel lines seen in stand Shewhart control charts. Last, we utilize the Box quadratic form and approximation to deal with the complexities of cumulative variance where means vary over time.
Keywords
SPC; Cumulative Square Cumulative Variance; EWMS EWMV
StartPage
247
EndPage
253
Doi
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