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|Author(s):||Nien F. Zhang; P Winkel;|
|Title:||Comparisons of Estimators of process standard deviation in constructing Shewhart control charts with unequal subgroup sizes|
|Published:||January 20, 2010|
|Abstract:||The and control charts with unequal subgroup size have been discussed in the literature and used in practice. Several estimators of the process standard deviation based on sample standard deviations have been proposed in constructing the charts. We discuss the properties of these estimators and make comparisons using the criterion of minimum mean square error. The and control charts based on the recommended estimator of the process standard deviation is also discussed|
|Keywords:||Biased Estimator,Control limit,Linear combination,Minimum variance,Relative difference|
|PDF version:||Click here to retrieve PDF version of paper (108KB)|