Nonstationary model for assessing human reliability

When the performance of any electrical or electronic system is interrupted by allegedly human errors, many opinions are voiced about human reliability. Based on an 11-year database, the authors present an analysis of the performance of a digital computer system and reveal some of the statistical patterns of computer interruptions (i.e. the time of occurrence of the interruptions) caused by computer operator errors. The significance of human errors in relation to all modes of computer system failures is discussed. A nonstationary model for estimating computer system reliability levels is presented. A case study is reported to illustrate the application of the proposed model and existing reliability models