Selection of Inspection Intervals Based on Multi-attribute Utility Theory

In the context of complex equipment, inspection has an important role to play in maintaining operations at a suitable performance. In fact, for this kind of system, failures are not immediate. Therefore, the concept of delay time is very useful as a two-step failure process, as a basis for constructing inspection models. Another aspect worth noticing is the fact that, in practice, when the decision-maker decides on the time between inspections, he/she takes different aspects into account in a non-structured way. This happens because the majority of inspection models deal with the problem using an optimization approach, where only one aspect is considered. So, the main contribution of this article is to put forward a multicriteria decision model in order to aid maintenance planning. This model takes the decision maker's preferences into account, as well as, the most important aspects, when considering setting the inspection intervals for periodic condition monitoring, and which are the cost and downtime associated with the inspection policy.