As part of its efforts to ensure that the utilities are taking all reasonable measures to maintain optimum performance of their power plants, the New York State Department of Public Service (DPS) initiated power-plant performance audits of the seven utilities in the state. All audit of the Long Island Lighting Company (LILCO) was performed, and the results are discussed. The objective of the audit was to make a comprehensive study of the power-plant operations and programs relating to the performance of the generating units and to identify areas of potential improvement. The assessment of performance covered 10 fossil units totaling about 2500 MW with an average age of over 25 years. The audit was carried out over the period of January 1987 through August 1988. The process involved an examination of plant equipment design and operational data, interviews with plant. head office. engineering and training personnel, and site inspections. Computer modeling was used to identify heat rate losses, which are then subjected to root cause analyses with remedial measures evaluated in terms of costs and benefits. Operating practices, fuel purchasing, water chemistry, and maintenance and performance improvement projects were also examined. >