State Diagram-Based Life Cycle Management Plans for Power Plant Components

Life cycle management (LCM) combines a set of technical and economic activities with the specific goal of improving the long-term economic value of an asset. An LCM plan helps to make operational decisions for a component over its life cycle. It typically consists of preventive maintenance scheduling, condition monitoring, inspection activities, replacement or refurbishment planning, and spares management. It is developed based on a study of component failure modes, operating history, maintenance practices, aging, spares, and obsolescence. Utility companies have predominantly developed LCM plans based on heuristic approaches. The existing methods do not accurately cover the impact of maintenance on equipment reliability and cost. A state diagram is developed to simulate the aging, inspection, maintenance, repair, failure, and overhaul cycle of a component throughout its lifetime. This diagram can help in deciding the optimal maintenance policy, and also quantify the impact of maintenance on reliability and cost. Probabilistic tools are also developed to help in the evaluation of an LCM plan and for further optimization.