What is the actual purpose of the SRPE–only board reviews, or used in conjunction with appraisals?

As per SRPE Policy, dated 10 July 2015, Paragraphs 3a and 3b, the SRPE is not to be used in conjunction with the various performance appraisal systems. One use of the SRPE is a part of the application process for Centralized Selection List (CSL) boards, the competitive development group/army acquisition fellows (CDG/AAF) program, and certain senior service college (SSC) programs. The SRPE is also a Talent Management tool enabling comparison of civilian grade/broadband structure with the incumbents in those positions.