Abstract
This paper considers the interval reliability of a repairable system for the time interval [T, T+x], Optimum preventive maintenance policies maximizing (i) the limiting interval reliability when T is constant, and (ii) the interval reliability when T is exponential, and minimizing (iii) the expected cost per unit of time, are derived, It is shown that under suitable conditions there exist optimum policies which are given by unique solutions of equations, Further this paper treats discrete case.
