Effect of Estimation on Simple Linear Profile Monitoring under Non-normality
Makaleler > Tam Makale · 2019
Yazarlar: Burcu AYTAÇOĞLU, Özlem Türker Bayrak
Süleyman Demirel Üniversitesi Fen Bilimleri Enstitüsü Dergisi, Hakemli Üniversite Dergisi, Uluslararası, TR Dizin (Ulakbim), 2019, cilt 23, ss 251-262
DOI: 10.19113/sdufenbed.506918
Özet
In recent years, many control charts have been proposed to monitor profiles where the quality of a process/product is expressed as function of response and explanatory variable(s). The methods mostly assume that the in control parameter values are known in Phase II analysis and innovations are normally distributed. However, in practice, the parameters are estimated in Phase I analysis and innovations may be non-normal. In this study, the performance of T2, EWMA-R and EWMA-3 methods for monitoring simple linear profiles is examined via simulation where the parameters are estimated and innovations have Student’s t-distribution. As a performance measure, both the average and standard deviation of the run length is considered. Finally, some recommendations for practitioners are summarized in a table.