期刊名称：Computational Methods in Science and Technology
印刷版ISSN：1505-0602
出版年度：2015
卷号：21
期号：4
页码：221-227
DOI：10.12921/cmst.2015.21.04.006
出版社：Poznan Supercomputing and Networking Center
摘要：The goal of this work is to detect any potentially harmful change in a process. The reliability tests are assumed to generate type-I right-censored data following a log-logistic distribution with scale parameter (η) and shape parameter (β). For this purpose, we have constructed a likelihood ratio based simultaneous cumulative sum (CUSUM) control chart that targets changes in both the failure mechanism and the characteristic life (the simultaneous CUSUM chart for detecting shifts in the shape and the scale parameters). This control chart displays best performance for combinations with larger positive or negative shifts in the shape parameter, signaling on average in 5 samples in an out-of-control situation, while targeting an in-control average run length of 370. The simultaneous CUSUM chart’s performance is highly dependent on the values of β, and on the interaction between them and the censoring rates and shift sizes.
其他关键词：Likelihood ratio, Type-I right-censoring, Log-logistic distribution, Cumulative sum (CUSUM) chart, Average run length
