Decision Matrix

Origin. Pugh controlled convergence; weighted-sum multi-attribute value theory.

Mechanism. Scores alternatives against weighted criteria and sums. Its real function is not the arithmetic but the externalization: the weights become arguable, and disagreement about the conclusion is relocated to disagreement about a weight, which can be resolved.

Procedure. Criteria as columns, weighted. Alternatives as rows. Score each cell. Weighted sum. Then perform the essential step: perturb the weights and see whether the winner changes. If it does, the matrix has decided nothing and the disagreement is about the weights.

Applies to. Selection among a fixed, small, comparable option set.

Limitations. Weighted-sum aggregation assumes preferential independence among criteria and full compensability — a fatal deficiency offset by an abundant strength. Where a criterion is a threshold, it must be applied as a filter before the matrix, never as a column in it. Weights are also routinely reverse-engineered from a preferred conclusion.