Management decisions regarding maintenance protocols critically hinge on the underlying probability
distribution of the time between failures in most repairable systems. Replacement of the system with
a new one resets the system age to zero, whereas a repair does not alter the system age but may shift
the parameters of the failure-time distribution. Additionally, maintenance decisions lead to left-truncated
observations, and right-censored observations. Thus, the underlying stochastic process governing a
repairable system evolves based on the management decision taken.