This paper deals with proposition of a maintenance methodology to be utilized in smart grid, which, in turn, may ensure reliability and security levels, minimize operation costs, reduce service interruptions and shortened outage durations. In this way, Reliability-Based-Maintenance (RCM) incorporated with economical rankings to achieve Predictive RCM (PRCM). The proposed methodology takes into account the individual equipments tasks to provide Independent System Operator (ISO) with system security and reliability monitoring tool. It evaluates each equipment condition and impact on the system reliability to manage the overall system maintenance. The methodology categorized the equipments based on their condition into three clusters. These are bad condition which maintenance or replacement is required, medium condition which maintenance should be done and good condition which maintenance is not required. The equipment condition is employed in the scheduling of sufficient generation units by ISO to provide load, which, in turn, may ensure system reliability. The maintenance task could be done based on the importance of each one in respect to system reliability in order to reduce services interruptions. Economical ranking is tackled into the problem formulation to improve the proposed methodology efficiency.
