Reliability Estimation and Confidence-interval for Two-unit System in the Presence of Common Cause Failures and Human Errors

This paper discusses the estimation of reliability measures of two unit system with identical components in the presence of chance Common Cause Shock (CCS) failures as well as human errors. The Maximum likelihood (M L) approach has been followed for the present model. The M L estimates of system reliability measures like reliability function[R(t)], mean time between failures (MTBF) were developed. The estimates were derived for both series and parallel systems. We also developed the confidence interval for the present study. The empirical evidence was developed by using Monte-Carlo simulation for selected values of the failure and repair rates to establish the validity and precision of the M L estimates of the above said reliability measures.