||Unit capability factor is defined as the ratio of the available energy generation over a given time period to the reference energy generation over the same time period, expressed as a percentage. Both of these energy generation terms are determined relative to reference ambient conditions. Available energy generation is the energy that could have been produced under reference ambient conditions considering only limitations within control of plant management, i.e., plant equipment and personnel performance, and work control. Reference energy generation is the energy that could be produced if the unit were operated continuously at full power under reference ambient conditions. Reference ambient conditions are environmental conditions representative of the annual mean (or typical) ambient conditions for the unit. The unit capability factor is determined for each period as shown below: value for a unit: UCF (%) = (REG - PEL - UEL)/REG x 100 %? Where: -REG = reference energy generation for the period -PEL = total planned energy losses for the period -UEL = total unplanned energy losses for the period? The purpose of this indicator is to monitor progress in attaining high unit and industry energy production reliability. This indicator reflects effectiveness of plant programs and practices in maximizing available electrical generation, and provides an overall indication of how well plants are operated and maintained.