Interval-valued availability of a standby system with imperfect switch incorporating uncertainty & multiple failure modes

ABSTRACT This paper examines the interval-valued availability of a standby redundant system with imperfect switching, incorporating uncertainty, i.e. the probability of successful operation of the switch is not known with accuracy. The standby system undergoes periodic inspections and is vulnerable to α number of failure modes (FMs). Every FM has a random failure time assigned to it, and once the system fails from the a th FM, a corrective repair is executed promptly. The corrective repair takes a random amount of time . Incorporating the aforesaid points, expressions for the upper and lower bounds of the model’s point and long-run availability are derived, and a sensitivity analysis is done to evaluate the impact of inspection time on the system’s availability. Lastly, the derived theorems are established by using a numerical example of a combi-boiler standby system with an imperfect switch.