A maintenance strategy for systems subjected to deterioration governed by random shocks

The authors examine the time-stationary availability of maintained systems that deteriorate according to a random-shock process. System failures are not self-announcing; hence, failures must be detected via inspection. The approach considers randomly occurring shocks that cumulatively damage the system; shock magnitudes are taken as random. The authors develop an expression for computing system availability when inspections follow a renewal process. This expression leads to a proved proposition showing that, for any specified mean inspection rate, system availability is maximized by choosing deterministic inter-inspection times