| How can objectives be concise without omitting what matters? | Inspect means–ends structure, relevance, overlaps, and sensitivity to simplification. | Retain an exhaustive descriptive hierarchy, or delete criteria by correlation alone. | Adapt: :4.2–:4.3 keep a small consequence-led account and test any lost distinction. More analyst attention is accepted where it prevents double counting; small clear cases remain short. | Marttunen et al.’s 2019 objectives-hierarchy study supplies the comparative methods and retrospective environmental cases. It supports disciplined simplification, not one optimal hierarchy or a statistical license to discard values. | Reopen when a removed distinction can reverse the comparison or a lighter structure preserves the same concerns. |
| Must incomplete preferences become one weighted score? | Construct the preference model from consequence comparisons and use all compatible instances. | Fit one additive score, average weights, or retain a noncompensatory rule when that better expresses the judgement. | Adapt: :4.5.1–:4.5.5 develop form selection, joint constraints, feasibility, necessary/possible comparison and local revision; :5.5–:5.6 show a complete use and failure of the affine form. The trade-off is a potentially less decisive answer for less invented precision. | Greco, Słowiński and Wallenius’s 2025 MCDA review, especially §3.1.2 and §7.1 (accessible author-hosted PDF), supplies preference assessment and robust ordinal regression. Its rules and non-additive families remain serious alternatives. The two-criterion derivation and service cases here are bounded applications, not its empirical findings or a universal additive-representation theorem. | Reopen when new judgement changes the compatible set, an interaction defeats the form, or the holder, range or governing condition changes. |
| Can common coordinates perform the value judgement? | Declare meanings and scales separately from preference, comparison, and selection. | Treat a dashboard or normalized vector as the decision model. | Adopt: :4.3 uses A.19 only for the declared space or predicate and leaves value elicitation here. The distinction adds little effort to an existing table and prevents a false consumer result. | Current A.19, C.16, and the direct comparison patterns supply the relevant typing and operation boundaries. They do not elicit the engagement’s values or authorize a trade-off. | Reopen when the scale, predicate, consequence range, or receiving use changes. |