ABSTRACT
In a number of practical situations, components and systems are repairable, that is, after a failure they undergo maintenance actions that do not consist in their entire replacement (Rigdon & Basu 2000). Moreover, such maintenance actions often restore the system to an intermediate condition between ‘‘as good as new’’ and ‘‘as bad as old’’ conditions, that is, imperfect repairs are performed. In order to model failure-repair processes of systems subjected to imperfect repairs, Generalized Renewal Processes (GRP-Kijima & Sumita 1986) can be applied.
