Availability of a Complex System Under Several Repair Preemptions

Availability of a complex system with two subsystems is evaluated. The failure and repair time of subsystems have exponential and general distributions respectively. Both subsystems are repaired under either of two repair policies, viz. Head-of-line and Preemptive Repeat. Supplementary variable technique and Laplace transform of time to failure have been used to obtain the Laplace transform of various transient state probabilities. Derivations are in a separately available Supplement.