Operational behaviour of a three state standby redundant electronic equipment under critical human errors

Abstract This paper deals with the operational behaviour of a cold-standby redundant system incorporating the concept of three states, with four types of failures, namely major unit failure, minor unit failure, partial failure due to critical human errors and complete failure due to critical human errors, under only one repair facility. Failure and repair times for the complex system follow exponential and general distributions, respectively. Repair is undertaken only when the system is either in degraded state or in failed state. Laplace transforms of the probabilities of being in various states as well as in up and down states are computed, along with the steady state behaviour of the system. A particular case of such a system has also been appended to highlight the important results.