Probabilistic evaluation of deterioration processes with maintenance activities

Reliable operation of contemporary complex systems depends on selecting efficient maintenance policy, which often must take into account not only the reliability, but also economic factors. In this work, we present an approach which allows evaluation of various possible maintenance scenarios with respect to these two areas. The method is based on the concept of a life curve and discounted cost used to study the effect of equipment aging under different maintenance strategies. The deterioration process is first described by a Markov model and then its various characteristics are used to develop the equipment life curve and to quantify other reliability parameters. Based on these data, effects of various “what-if” maintenance scenarios can be examined and their efficiency compared. Simple life curves are combined to model equipment deterioration undergoing diverse maintenance actions, while computing other parameters of the model allows evaluation of additional critical factors, such as probability of equipment failure. Additionally, the paper deals with the problem of the model adjustment so that the computed frequencies are close to the historical values, which is very important in practical applications of the method.