This work addresses the modelling of the effects of maintenance on the degradation of an electric power plant component. This is done within a modelling framework previously proposed by the authors, of which the distinguishing feature is the characterization of the component living conditions by influencing factors (IFs), i.e. conditioning aspects of the component life that influence its degradation.The original fuzzy logic-based modelling framework includes maintenance as an IF; this requires one to jointly model its effects on the component degradation together with those of the other influencing factors. This may not come natural to the experts who are requested to provide the if-then linguistic rules at the basis of the fuzzy model linking the IFs with the component degradation state. An alternative modelling approach is proposed in this work, which does not consider maintenance as an IF that directly impacts on the degradation but as an external action that affects the state of the other IFs. By way of an example regarding the propagation of a crack in a water-feeding turbo-pump of a nuclear power plant, the approach is shown to properly model the maintenance actions based on information that can be more easily elicited from experts.

In this paper, a modelling approach is presented to assess the performance of multicomponent systems maintained by complex maintenance strategies. A global framework is built to describe the evolution of the system, the way its components can degrade and fail, and the effects of different maintenance actions. A two-level modelling framework makes it possible to describe fully the entire causal chain that can lead to system dysfunction and the possible maintenance tasks of the reliability centred maintenance (RCM) method. A cost model is defined to assess system performance in terms of cost and unavailability. The main originality of this work is that the complexity of both maintenance programmes and system structures is taken into account. The model can be used as a decision-making tool to choose from a selection of various maintenance options. Promising results have been obtained in case studies based on systems from nuclear power plants.

International audienceIn this article, the problem of building a model in support of maintenance optimization when the only available information is that elicited from one expert is tackled. In particular, the degradation process affecting the component is modeled by resorting to the concept of effective age. Information is elicited from one expert by following a systematic literature approach, and the theoretical framework of fuzzy logic is used to deal with his or her qualitative statements. A hybrid approach based on Monte Carlo method and fuzzy logic is then applied to evaluate the performance of a given maintenance policy. Finally, the proposed methodology is applied to a real case study dealing with a medium-voltage test network

No abstract

No abstract