Abstract: 40% of all failure modes of complex industrial systems fall into the category of hidden failures. It is likely to cause huge economic losses if these hidden failures are not eliminated in time. In this paper, the maintenance strategy problem of a multi-state competing failure system with hidden failures is studied by considering imperfect inspection. Firstly, all the renewal scenarios of the system are analyzed according to the given condition-based maintenance strategy. Then, the occurrence possibility of each renewal scenario is derived, based on which the maintenance model is established. The constructed maintenance model takes the expected cost rate as the objective and the inspection interval as the optimization variable. Finally, a capacitor bank is taken as an example to verify the applicability and effectiveness of the proposed maintenance model. The results show that inspection quality has an important influence on the decision-making of the inspection strategy. Therefore, inspection errors should be considered when constructing maintenance model. The modeling method proposed in this paper can not only enrich the maintenance strategy theory and method of multi-state competing failure systems to a certain extent, but also provide theoretical basis and decision-making basis for the maintenance of complex industrial systems in engineering practice.

Key words: hidden failure;multi-state competing failure system; imperfect inspection; condition-based maintenance