Evaluation Criteria and How Sources Are Selected

Evaluation is where a proposal stops being a document you wrote and becomes a record the government builds about you. Understanding how that record gets constructed, adjective by adjective and finding by finding, is what separates a proposal team that writes for the evaluator from one that writes for itself.

Best value tradeoff versus lowest price technically acceptable

FAR Part 15 recognizes two dominant source selection approaches. Under best value tradeoff, the government may pay more for a proposal that offers superior technical merit, more capable key personnel, or lower performance risk, provided the contracting officer documents why the added cost is worth the added value. Under lowest price technically acceptable, technical merit above the acceptable threshold earns no credit at all; once a proposal clears the bar, price becomes the only remaining discriminator.

The choice between the two shapes how you should write. A best value proposal rewards genuine technical differentiation and calculated risk-taking in your approach. An LPTA proposal rewards clearing every acceptability standard cleanly and then competing hard on price, because writing an excellent technical volume beyond the acceptability threshold buys you nothing under that evaluation scheme.

Adjectival ratings

Most NASA technical evaluations translate written findings into an adjectival rating, a scale such as outstanding, good, acceptable, marginal, and unacceptable, sometimes with additional gradations. The adjective is not decorative. It is meant to summarize, in a single word tied to a defined standard, the balance of strengths and weaknesses an evaluator found in that factor. A rating of good with three significant strengths and one minor weakness reads very differently to a source selection authority than a rating of good built on a single strength and no weaknesses, even though the adjective is identical, which is why the underlying narrative findings matter more than the label.

Strengths, weaknesses, significant weaknesses, and deficiencies

• Strength: an aspect of a proposal that exceeds a requirement or increases the likelihood of successful performance in a way beneficial to the government.
• Significant strength: a strength that appreciably increases the likelihood of successful performance.
• Weakness: a flaw that increases the risk of unsuccessful performance.
• Significant weakness: a flaw that appreciably increases the risk of unsuccessful performance.
• Deficiency: a material failure to meet a requirement, or a combination of weaknesses so severe that performance risk becomes unacceptable, as defined at FAR 15.001.

A single deficiency can make a proposal unawardable on that factor regardless of how many strengths accompany it, which is why proposal reviews should hunt for deficiencies first and polish for strengths second.

The source evaluation board and the source selection authority

On larger NASA procurements, a source evaluation board of subject matter experts reviews proposals against the factors in Section M, documents findings, and assigns ratings. The board's job is to produce an accurate, well-supported record, not to make the award decision. That decision belongs to the source selection authority, who reviews the board's findings, may ask clarifying questions, and independently weighs the tradeoffs described in Section M before selecting an awardee. On many procurements the contracting officer serves as the source selection authority; on larger or higher-visibility acquisitions NASA may designate a more senior official for that role.

Competitive range, discussions, and final proposal revisions

After initial evaluation, the contracting officer may establish a competitive range under FAR 15.306, consisting of the most highly rated proposals, and eliminate the rest from further consideration. Offerors within the competitive range may be invited into discussions, during which the government communicates weaknesses, significant weaknesses, deficiencies, and adverse past performance information specific to that offeror's own proposal. Discussions are not an opportunity to coach an offeror toward a better answer; they are meant to give every offeror in the range a fair chance to address issues actually identified in their own submission.

Discussions typically close with a request for final proposal revisions, a single closing opportunity to submit your best and final offer. After that point, no further negotiation occurs, and the source selection authority makes the award decision based on the final record.

The source selection decision document

The source selection decision document is the written record the source selection authority produces to justify the award. It must trace a defensible line from the evaluation findings to the tradeoff conclusion, particularly under best value tradeoff, where the document has to explain in specific terms why any price premium paid for the winning offeror was worth it. This document is a frequent focal point in bid protests, discussed in Chapter 16, because a poorly reasoned tradeoff rationale is one of the more common grounds on which the Government Accountability Office sustains a protest.

Understanding that this document exists, and what it must contain, changes how a proposal writer should frame discriminators. A strength buried in prose without a clear, quantifiable benefit is much harder for a source selection authority to cite in a defensible tradeoff rationale than one stated plainly enough to be lifted directly into that record.