Defines life cycle costing, which gives rise to Life Cycle Cost (LCC). Defines LCC as “The total cost of the system or product under study over its complete life cycle or the duration of the period of study, whichever is the shorter”. Stresses that LCC can be used at whatever level is chosen (estate or, say, a boiler). Explains the timing and mechanism of measurement. Argues that the application of LCC at an early design stage will greatly enhance system design and operation. Offers other pertinent definitions.