Approximately optimal simple inspection strategies

In the paper we present a very simple method for finding an approximately optimal strategy of inspections of an equipment whose failures are not directly observable. The optimal inspection interval can be found with a limited amount of information using simple computational methods. We consider also the impact of imprecise input information on the computed values of optimal inspection periods. In such a case we describe imprecise numerical information by fuzzy sets, arriving at the imprecise (fuzzy) optimal inspection interval.