A two-dissimilar-unit cold standby system with allowed down time

This paper considers a two-dissimilar-unit cold standby system under a very general set of assumptions. A system breakdown is said to occur if both the units are down. The system fails if the system breakdown is not repaired within the allowed time. The Laplace-Stieltjes transform of the distribution of the time to system-failure; the probabilities of the system being in up, down and failed states; the generating function of the number of visits to the down state before system failure; have all been obtained. Particular cases correspond to the results obtained earlier in the literature.