[Code of Federal Regulations] [Title 48, Volume 1] [Revised as of October 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 48CFR15.001] [Page 253] TITLE 48--FEDERAL ACQUISITION REGULATIONS SYSTEM CHAPTER 1--FEDERAL ACQUISITION REGULATION PART 15_CONTRACTING BY NEGOTIATION--Table of Contents Sec. 15.001 Definitions. As used in this part-- Deficiency is a material failure of a proposal to meet a Government requirement or a combination of significant weaknesses in a proposal that increases the risk of unsuccessful contract performance to an unacceptable level. Proposal modification is a change made to a proposal before the solicitation closing date and time, or made in response to an amendment, or made to correct a mistake at any time before award. Proposal revision is a change to a proposal made after the solicitation closing date, at the request of or as allowed by a contracting officer, as the result of negotiations. Weakness means a flaw in the proposal that increases the risk of unsuccessful contract performance. A ``significant weakness'' in the proposal is a flaw that appreciably increases the risk of unsuccessful contract performance. [62 FR 51230, Sept. 30, 1997, as amended at 66 FR 2129, Jan. 10, 2001]