Quality control charts for censored and non-normal data.

摘要

Statistical quality control charting methods are needed for processes generating lifetime data, possibly subject to censoring. A Shewhart charting method based on Generalized Least Squares estimates is developed here which may be applied to any member of a location-scale family or to any distribution that can be transformed to a location-scale family. Its use is demonstrated for Type II order censored samples from the log-Normal and Weibull distributions, and its performance properties are evaluated. A cumulative sum charting method based on the sequence of Maximum Likelihood Estimates is developed here which may be applied to a variety of distributions Its use is demonstrated for Type I value censored Normally distributed data, and its performance properties are evaluated.