Reliability modeling of repairable systems deals mostly with two types of repair. Perfect repair brings a system to “as good as new” state. Minimal repair, on the contrary, returns a system to the state immediately prior to failure. In this article, we consider perfect and imperfect preventive maintenance actions for a system subjected to minor and major failures. Minor failures are minimally repaired, whereas a major failure terminates the operational function of the system and can be considered as an end-of-life event. The preventive maintenance strategies that we propose and analyze increase mission success probability and extend the expected lifetime of the system. The modeling is illustrated with numerical examples.