Repairable systems with general repair

A repairable system can briefly be characterized as a system which is repaired rather than replaced after a failure. The most commonly used models for the failure process of a repairable system are nonhomogeneous Poisson processes, corresponding to minimal repairs, and renewal processes, corresponding to perfect repairs. The paper reviews models for more general repair actions, often called "imperfect repair" or "better-than-minimal repair" models, using a general framework based on point process theory. A Markov model approach for periodically tested components is also considered.