Modeling human errors in repairable systems

The author presents the reliability analysis of repairable and nonrepairable redundant systems with human errors and common-cause failures. Parallel, k-out-of-n, and standby systems are studied. Reliability, mean-time-to-failure, steady-state availability, and variance-of-time-to-failure formulas are developed. Some plots are presented. The plots clearly demonstrate that system steady-state availability, mean-time-to-failure, and reliability decrease with increasing values of human error rate