What is a major factor in determining whether a proposal is responsive under FAR?

A proposal is considered responsive under the Federal Acquisition Regulation (FAR) primarily based on its completeness. This means that the proposal must meet all the requirements specified in the solicitation. Completeness includes adhering to the format, addressing all technical specifications, and providing all necessary documentation required for evaluation. If a proposal is missing crucial elements or fails to comply with the solicitation's instructions, it may be deemed non-responsive, which could lead to disqualification from the bidding process.

The other factors, while relevant to the overall evaluation of a bidder's qualifications, do not primarily determine responsiveness. The proposed cost is important for negotiations and final contract terms but does not affect whether the proposal meets the solicitation's requirements. Similarly, the number of previous contracts held or average performance ratings provides insight into the bidder's experience and reliability but does not directly relate to the current proposal's responsiveness. Therefore, the completeness of the proposal submission is the key determinant in establishing its responsiveness under FAR guidelines.