1. EWMA Charts for Monitoring the Mean of Censored Weibull Lifetimes.
- Author
-
Lingyun Zhang and Gemai Chen
- Subjects
WEIBULL distribution ,DISTRIBUTION (Probability theory) ,ARITHMETIC mean ,PROCESS control systems ,QUALITY control charts - Abstract
A lower-sided and an upper-sided exponentially weighted moving average (EWMA) chart for detecting mean changes (decreases and increases) in processes characterized by Weibull distributions are developed in this paper when censoring occurs at a fixed level. We show that the lower-sided EWMA chart performs better than its counterpart, the Shewhart-type; that a Shewhart-type chart is not appropriate to detect mean increases when the censoring rate is high; and that the upper-sided EWMA chart works well in detecting mean increases. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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