Çok değişkenli kalite kontrol çizelgelerinin döküm sanayiinde uygulanması

Kontrol çizelgelerinin kullanım amacı, bir süreçteki kalite değişkenlerinin normal dışı davranışlarını belirlemek ve bundan hareketle hata kaynaklarını ortaya çıkarmaktır. Çok değişkenli kalite kontrol çizelgeleri arasında en popüleri olan Hotelling T2 çizelgeleri, birden fazla kalite değişkenini eşzamanlı gözlemek için kullanılır. Bu çalışmada Hotelling T2 çizelgeleri, bir pirinç döküm fabrikasında pirinç eritme sürecine uygulanmıştır. Süreç kontrol altındayken toplanan çok değişkenli süreç verilerine dayalı olarak Hotelling T2 çizelgesi oluşturulmuş, ardından çizelge yeni süreç verilerine uygulanmıştır. Kontrol dışı durumlara işaret eden çizelge sinyalleri incelenmiş, süreci iyileştirmek amacıyla hata kaynakları araştırılmıştır. Bu araştırmada Mason-Young-Tracy ayrıştırma yönteminden yararlanılmıştır.

Application of multivariate statistical process control in casting industry

The purpose of quality control charts is to detect abnormal behavior of quality variables and to determine the causes of quality problems using these abnormalities. Hotelling’s T2 charts, the most popular multivariate quality control charts, are used to monitor several quality variables, simultaneously. In this study, Hotelling’s T2 charts were applied to a melting process in a brass casting factory. A Hotelling’s T2 chart was formed from multivariate data collected from the process when it was in control; then, the chart was applied to new process data. Chart signals that are out of control limits were analyzed, and associated root causes were investigated in order to improve the process. Mason-Young-Tracy decomposition method was employed in this investigation.

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