A term used in public utility regulation to mean the total number of dollars required to supply any total utility service (i.e., revenue requirements); it must include all of the supplier's costs, an amount to cover operation and maintenance expenses, and other necessary costs such as taxes, including income taxes, depreciation, depletion, and amortization of the property not covered by ordinary maintenance. Included also is a fair return in order that the utility can maintain its financial integrity, attract new capital, and compensate the owners of the property for the risks involved. A "cost of service study" is made in order to assist in determining the total revenue requirements to be recovered from each of the various classes of service. The amounts to be recovered from each of the classes of service are determined by the management or a commission after study of the various factors involved in rate design. Cost analysis or cost allocation is an important factor in rate design but only one of several important factors. Cost analysis does not produce a precise inflexible "cost of service" for any individual class of service because cost analysis involves judgement in certain cost areas. Its principal value is in determining the minimum costs attributable to each class of service. Other factors that must be considered in rate design are the value of the service, the cost of competitive services, the volume and load factor of the service and their relation to system load equalization and stabilization of revenue, promotional factors and their relation to the social and economic growth of the service area, political factors such as the sizes of minimum bills, and regulatory factors.