Koppisetti Vani Saisrinivas

N Ravinder Reddy

VV Satyanarayana

N Suguna

Abstract

Schewart Quality Control (SQC)charts are essential in any production process in order to sustain the quality in the product which is to be made acceptable for use by a customer. The maintenance of SQC charts for individual Quality Characteristics of a product is cumbersome; It gets multiplied with the number of variables ofthe product and hence can be simplified with the help of multivariate quality charts. The maintenance of a single multivariate quality chart which includes similar and dissimilar quality characteristics of a product makes the on line quality control work more simple. However the exact quality characteristic of the product causing out of control signal is difficult to identify and can be found by various methods. In this investigation MYT decomposition method is employed to identify the assignable cause.

Keywords- T2-Control Charts, MYT (Mason, Young and Tracy) Approach, SQC, decompositionprocedure, Mean chart, Range chart.