Comparing the Benefits of Monitoring Versus Preemptive Replacement or Repair
Today, utilities are faced with many equipment maintenance decisions, including whether to implement periodic replacement or to begin an inspection or condition monitoring program. Determination of an optimum maintenance strategy can be difficult because of the financial implications and the probabilistic aspect of the aging process. The Proactive Aging Management (PAM) Tool is a program that can be implemented by utilities to achieve maintenance optimization. PAM supports the decision making process by providing a financial analysis that assesses the impact of outage, inspection, repair and replacement costs together with the effects of aging on the failure rates of a particular component. PAM evaluates the present value of each maintenance strategy and optimizes maintenance parameters such as replacement date or inspection frequency. Component level models in PAM allow the system engineer to determine the best maintenance strategy for a given component. This paper describes an application of PAM that compares the options of inspection or proactive replacement to a base case run-to-failure strategy. The net present value (NPV) over the life of the plant is the metric by which strategies are compared. The NPV is generated for several combinations of inspection and proactive replacement costs. The results provide insight on the optimum choice based on the respective relative costs of each strategy.