Estimation of Process Variance in Using Spc Charts for a Stationary Process
نویسنده
چکیده
Recently, statistical process control (SPC) methodologies have been developed to accommodate autocorrelated data. To construct control charts for stationary process data, the process variance needs to be estimated. For an independently identically distributed sequence of a random variable, the variance is usually estimated by the sample variance. For a weakly stationary process, different estimators of the process variance can be used. In this paper, comparisons of estimators of the process variance are made based on the criterion of minimum mean squared error.
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