Establishing an Evaluation Rating Method
A rating system uses a scale of words, colors, numbers or other indicators to denote the degree to which proposals meet the standards for the non-cost evaluation factors. Thus, assessments of each proposal are made with respect to the evaluation factors and subfactors in the solicitation using a rating system. Some commonly used rating systems are adjectival, color coding, and numerical.
Rating systems which use adjectives or colors are usually the most successful because they allow maximum flexibility in making the tradeoffs among the evaluation factors. A narrative definition must accompany each rating in the system so that evaluators have a common understanding of how to apply the rating. For example, a rating of exceptional (or blue or 90-100) could be defined as meaning an outstanding approach to specified performance with a high probability of satisfying the requirement. What is key in using a rating system in proposal evaluations, is not the method or combination of methods used, but rather the consistency with which the selected method is applied to all competing proposals and the adequacy of the narrative used to support the rating.
- Adjectival
Adjectives (such as exceptional, good, satisfactory, marginal, and unsatisfactory are used to indicate the degree to which the offeror's proposal has met the standard for each factor evaluated. Adjectival systems may be employed independently or in connection with other rating systems.
- Color Coding
This system uses colors to indicate the degree to which the offeror's proposal has met the standard for each factor evaluated. For instance, the colors blue, green, yellow, amber, and red may indicate exceptional, good, satisfactory, marginal, or unsatisfactory degrees of merit, respectively.
- Numerical
This system assigns point scores (such as 0-10 or 0-100) to rate proposals. This rating system generally allows for more rating levels and thus may appear to give more precise distinctions of merit. However, numerical systems can have drawbacks as their apparent precision may obscure the strengths, weaknesses, and risks that support the numbers. Therefore, some organizations do not permit the use of numerical rating systems.
Narrative - Narrative is used in conjunction with a rating system to indicate a proposal's strengths, weaknesses, and risks. Adjectival, color, and numerical ratings must be supported with narrative statements. Narrative statements can describe the proposals' relative strengths, weaknesses, and risks to the source selection authority in a way that adjectives, colors, and numbers alone cannot. A narrative is required when evaluation standards are being applied, when a comparison of proposals is being made, and when a cost/technical tradeoff is conducted. The narrative provides a reasonable and rational basis for the selection decision.