Special Purpose Tools
In practice, TBL is typically applied using either a general-purpose framework or a special-purpose tool. Unlike general-purpose frameworks, special-purpose TBL tools are built around specific sets of quantified evaluation measures and provide subtotals and sometimes a single total score. Each special-purpose tool applies to some class of decisions: for example, economic development projects, infrastructure investments, or transportation plans.
Similar to a Consumer Reports rating, a TBL tool is built around a fixed list of quantitative or qualitative evaluation measures, typically organized into three (or more) categories and sometimes into subcategories, along with some system for combining or otherwise summarizing the evaluation measures. Some tools aim to determine the “right” decision: the choice with the highest score. Other tools report three or more scores, and leave it up to decision-makers to balance these. Still other tools allow decision-makers to specify different weights for combining evaluation measures or provide different methods for aggregating evaluation measures.
In all cases decision-makers choose and control the tools they use, not the other way around. If a tool doesn’t give a desired answer (or at least an answer that makes sense), perhaps it’s the wrong tool for the job!
