Evaluation of Generator Maintenance Schedules at Entergy Electric System

Manual evaluation of the impact of detrimental events on outage schedules in electric power plants is both subjective and time-consuming. We developed a decision-tree-based methodology that converts the manual evaluation process into a computerized package. It uses a special statistic instead of the (less-useful) expected value analysis that typifies textbook presentations. It also provides a systematic procedure for determining the branches and probabilities of the decision tree based on historical data. The Entergy Electric System has used the new tool for over three years to enable the outage planner to isolate, high-risk time periods and to develop timely maintenance schedules in response to short-notice changes.