Individual annual accounting analyses are carried out for operating and maintenance costs as a whole and for system. Also, individual monthly accounting analyses are carried out for main system facilities, these comprise, at the very least, the technical service units, customer service, units/crews of new investments and corrective maintenance. For these evaluations, individual and segregated accounting analyses are carried out for the main components of these operating costs.

Rates of return: Achieving a rate of return is an important aspect in ensuring that company activities are operating like comparable businesses. In cost management, setting appropriate rates of return for each separate line of commercial or technical activity is an important factor to avoid cross-subsidization. Only projects and initiatives with a reasonable rate of return can be executed. For SOEs, its productivity should be benchmarked with similar business activities in the same industry and private companies. For this evaluation minimally the following criteria must be used for new projects: (a) simple payback; (b) return on investment; (c) net present value; and (d) life-cycle cost.