How would you document a tradeoff analysis between numerous (more than 5) offerors? Would you need to compare each proposal to each other? Would you need to compare your apparent awardee to every other proposal? Or could you just state why the proposal you chose is the best value?
FAR 15.308 states: "The most important consideration is documenting the results of evaluating each proposal against the evaluation factors stated in the solicitation. The source selection authority’s (SSA) decision shall be based on a comparative assessment of proposals against all source selection criteria in the solicitation." In other words, the basic evaluation (first step in the process) rates each proposal against the solicitation's evaluation criteria rather than other proposals. Once each proposal is rated on its own merits using the adjectival ratings, those ratings serve as the basis for comparing which overall proposal provides the best value to the Government (the second step). The documentation for the first step addresses each offeror's rating against the solicitation's evaluation factors. If each proposal were to be compared to every other offeror's proposal for each rating factor, it would require 90 separate entries (assuming 10 offerors in the competitive range) for each separate evaluation factor. That is not practical, or required. However, it may be advisable to include some specific examples of how and why the top-rated proposal is considered superior to others.