Statistical Monitoring of Time-to-Failure Data Using Rank Tests


Zhiguo Li, Department of Industrial and Systems Engineering, The University of Wisconsin–Madison, Madison, WI 53706, USA.



A common type of reliability data is the right censored time-to-failure data. In this article, we developed a control chart to monitor the time-to-failure data in the presence of right censoring using weighted rank tests. On the basis of the asymptotic properties of the rank statistics, we derived the generic formulae for the operating characteristic functions of the control chart to show the relationship between type I error probability, type II error probability, sample size, and hazard rate change. We presented case studies to illustrate the design procedure and the effectiveness of the proposed control chart system. We also investigated and compared the performance of the proposed monitoring procedure with some available monitoring techniques for nonconformities. Copyright © 2011 John Wiley & Sons, Ltd.