5 U.S.C. § 4304

(a) The Office of Personnel Management shall make technical assistance available to agencies in the development of performance appraisal systems. (b) (1) The Office shall review each performance appraisal system developed by any agency under this section and determine whether the performance appraisal system meets the requirements of this subchapter. (2) The Comptroller General shall from time to time review on a selected basis performance appraisal systems established under this subchapter to determine the extent to which any such system meets the requirements of this subchapter and shall periodically report its findings to the Office and to the Congress. (3) If the Office determines that a system does not meet the requirements of this subchapter (including regulations prescribed under section 4305), the Office shall direct the agency to implement an appropriate system or to correct operations under the system, and any such agency shall take any action so required.