Online Reliability and Risk to Schedule the Preventive Maintenance in Network Utilities

This paper presents a methodology and a case study where the proportional hazard model is used to determine reliability and risk of existing repairable systems in a distribution network utility. After introducing different issues relating to conditioning maintenance management in these companies, we discuss the modeling possibilities to obtain online values for systems reliability and risk. In this case we try to model reliability considering current operating time of the equipment, the number of maintenance interventions, and the value of specific monitored parameters. Reliability is then used to calculate equipment risk for a given failure mode during a certain period, and in order to do so, failure mode affection to the network is estimated from historical data. Finally, the paper presents a possible business process to schedule preventive maintenance activities according to previous findings and a case study.