This part of ISO 15663 provides guidance on application of the methodology for life-cycle costing for the development and operation of facilities for drilling, production and pipeline transportation within the petroleum and natural gas industries. This part of ISO 15663 also provides guidance on the application and calculations of the life-cycle costing process defined in ISO 15663-1.[1] This part of ISO 15663 is not concerned with determining the life-cycle cost of individual items of equipment, but rather with life-cycle costing in order to estimate the cost differences between competing project options.