Criticality-based maintenance of a coal-fired power plant

The need for an evolution from the consolidated RCM (Reliability Centered Maintenance) models is something that quite a few experts have been pointing out for quite some time now. Various authors are frequently considering the addition of different techniques in a RCM analysis to increase its efficiency and quality. The objective of this work is to present a method that identifies the most critical components of a system, in order to contribute to the prioritization of maintenance actions. The method uses reliability and risk analysis techniques, such as Hazard and Operability Study (HAZOP), Fault Tree Analysis (FTA) and Failure Modes and Effects Criticality Analysis (FMECA). It also uses a multi-criteria decision method, the Analytic Network Process (ANP), for ranking the most critical components. The method is applied in the Flue Gas Desulfurization System of a Coal-Fired Power Plant. The results obtained with the implementation of the method indicate the most critical components for which maintenance planners shall focus attention, aiming at increasing the availability and decreasing the risk in relation to the plant operation.