Government audit agencies and contract evaluation boards have voiced concern over the use of GSA Schedule rates as a basis of comparison for a FAR Part 15-type price analysis. There are several factors influencing this concern, including but not limited to the use of untracked and unverified costs in the build-up of GSA rates (TINA and CAS are not applicable to commercial item procurements and GSA Schedules are issued under FAR Part 12); and the inclusion of costs that are not ordinarily a factor in FAR Part 15 rates (like IFF).