48 C.F.R. §§ 9904.401-20
The purpose of this Cost Accounting Standard is to ensure that each contractor's practices used in estimating costs for a proposal are consistent with cost accounting practices used by him in accumulating and reporting costs. Consistency in the application of cost accounting practices is necessary to enhance the likelihood that comparable transactions are treated alike. With respect to individual contracts, the consistent application of cost accounting practices will facilitate the preparation of reliable cost estimates used in pricing a proposal and their comparison with the costs of performance of the resulting contract. Such comparisons provide one important basis for financial control over costs during contract performance and aid in establishing accountability for cost in the manner agreed to by both parties at the time of contracting. The comparisons also provide an improved basis for evaluating estimating capabilities.
48 C.F.R. §§9904.401-20