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Monitoring process mean level using auxiliary information
Author(s) -
Riaz Muhammad
Publication year - 2008
Publication title -
statistica neerlandica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 39
eISSN - 1467-9574
pISSN - 0039-0402
DOI - 10.1111/j.1467-9574.2008.00390.x
Subject(s) - control chart , x bar chart , \bar x and r chart , chart , statistics , mathematics , ewma chart , shewhart individuals control chart , estimator , bivariate analysis , computer science , process (computing) , operating system
In this study, a Shewhart‐type control chart is proposed for the improved monitoring of process mean level (targeting both moderate and large shifts which is the major concern of Shewhart‐type control charts) of a quality characteristic of interest Y . The proposed control chart, namely the M r chart, is based on the regression estimator of mean using a single auxiliary variable X . Assuming bivariate normality of ( Y , X ), the design structure of M r chart is developed for phase I quality control. The comparison of the proposed chart is made with some existing control charts used for the same purpose. Using power curves as a performance measure, better performance of the proposed M r chart is observed for detecting the shifts in mean level of the characteristic of interest.