key-assumptions-check

The Key Assumptions Check (KAC) is a core structured analytic technique from Richards Heuer and Randolph Pherson (Structured Analytic Techniques for Intelligence Analysis). It catches the failure where a conclusion rests on assumptions the analyst never noticed making, so when one breaks the whole structure falls. An assumption is anything taken as true, without current proof, to let the analysis proceed; the stated ones are rarely the problem, the unstated ones are. KAC surfaces every assumption, tests it, and reports which ones the answer depends on.

When to use

The user has an analysis, plan, recommendation, forecast, or estimate and wants to know what it silently rests on before committing. Triggers: "what are we assuming", "check the assumptions", "what is this resting on", "what if we're wrong about X", "pressure-test the premises".

Reach for it when the cost of an unexamined assumption breaking is high: a strategy that assumes a competitor won't react, a forecast that assumes the past pattern holds, a plan that assumes a dependency lands on time. Pairs with analysis-of-competing-hypotheses (ACH tests which hypothesis the evidence supports; KAC tests the assumptions both rest on) and pre-mortem (KAC finds the fragile premises; the pre-mortem imagines them failing).

Do not use it to gather evidence (KAC says which assumptions to verify, it does not verify them) or to choose between options on value grounds (use weighted-decision-matrix).

Inputs

• SUBJECT (required): the analysis, plan, claim, or forecast to check. Paste the reasoning, or the conclusion with its main supporting argument. If only a conclusion is given, ask for the reasoning behind it; assumptions live in the reasoning, not the headline.
• CONTEXT (optional): domain, stakes, the decision it feeds, constraints. Sharpens which assumptions are load-bearing.
• ROLE (optional): who relies on the analysis. Defaults to "a decision-maker about to act on this analysis."

Orchestration map