Linear Profile Monitoring in the Presence of Non-Normality and Autocorrelation
In an increasing number of practical situations, the quality of a process or product can be effectively characterized and summarized by a profile. A profile is usually a functional relationship between a response variable and one or more explanatory variables which can be modeled frequently using li...
Main Authors: | , , |
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Format: | Article |
Language: | English |
Published: |
Iran University of Science & Technology
2010-12-01
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Series: | International Journal of Industrial Engineering and Production Research |
Subjects: | |
Online Access: | http://ijiepr.iust.ac.ir/browse.php?a_code=A-10-14-2&slc_lang=en&sid=1 |
Summary: | In an increasing number of practical situations, the quality of a process or product can be effectively characterized and summarized by a profile. A profile is usually a functional relationship between a response variable and one or more explanatory variables which can be modeled frequently using linear or nonlinear regression models. In this paper, we study the effect of non-normality on profile monitoring in Phase II when within or between autocorrelation is present. Different levels of autocorrelation and skewed and heavy-tailed symmetric non-normal distributions are used in our study to evaluate the performance of three existing monitoring schemes numerically. Simulation results indicate that the non-normality and autocorrelation can have a significant effect on the in-control performances of the considered schemes. Results also indicate that the out-of-control performances of the schemes are not very sensitive to low and moderate levels of autocorrelation in moderate and large shifts . |
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ISSN: | 2008-4889 2345-363X |