SPSA algorithm for fuzzy random time inspection policy

The time inspection policy is one of the most common maintenance policies. In this paper, a time inspection policy is studied in which the lifetimes of components are treated as fuzzy random variables. The concept of the long-run expected cost per unit time is put forward. In order to minimize the long-run expected cost per unit time, a fuzzy random expected value model is established. The fuzzy random simulation technique is employed to estimate the value of the objective function and the simultaneous perturbation stochastic approximation (SPSA) algorithm is employed to search the optimal solution. Finally, a numerical example is presented to illustrate the effectiveness of the algorithm.