A Unifying Concept of X Chart and X-Bar Chart when Subgroup Sizes are Equal

Maman A. Djauhari

Abstract


X chart and X-bar chart are usually seen as two techniques in SPC with different concepts. In this paper we propose two propositions as a unifying concept for those two charts; one for start-up stage and the other for process control for future observations. Another advantage of this concept lies in the determination of control limits which is not based on approximation method anymore. An exact method will be introduced.

 

Konsep untuk Bagan Kendali X dan Bagan Kendali X-Bar Bila Ukuran Subgrupnya Sama

Bagan Kendali X dan bagan kendali X-Bar biasanya dipandang sebagai dua teknik Pengendalian Proses Statistik yang memiliki konsep yang berbeda. Dalam tulisan ini kami usulkan dua buah proposisi yang memungkinkan memandang kedua bagan kendali itu dari satu konsep yang sama. Proposisi pertama adalah untuk tahap awal pembuatan bahan kendali (start-up stage) dan yang lain untuk pengendalian proses melalui metode pendekatan seperti yang biasa dikemukakan dalam berbagai pustaka tentang pengendalian proses. Metode eksak akan diperkenalkan.


Keywords


bagan kendali X; bagan kendali X-Bar; tahap awal pembuatan bagan kendali (start-up stage); pengendalian proses; batas kendali; X Chart; X-Bar Chart; start-up stage; process control; control limits

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References


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