Facts, Assumptions, Constraints and Unknowns in a Decision Record
Use the FACU framework to separate evidence, beliefs, boundaries and missing information in a traceable decision record.
A decision record becomes more trustworthy when facts, assumptions, constraints and unknowns are labelled separately and each can change without silently rewriting the others.
The FACU evidence map
Classify each statement by what it is today, not by how confident the team feels about it.
- 01
Fact
A verifiable observation with a named source and date. A fact can become stale, so provenance matters as much as wording.
- 02
Assumption
A belief used to continue analysis before proof is available. Record its owner, impact and validation plan.
- 03
Constraint
A boundary the viable solution must respect, such as law, budget, timing or interoperability. Confirm who has authority to change it.
- 04
Unknown
A material unanswered question. Give it a next action and deadline instead of hiding it in meeting notes.
Example: identity integration
‘Single sign-on is mandatory’ may be a constraint; ‘every contractor has a corporate account’ is an assumption until identity data confirms it; the current account count is a dated fact; the onboarding method for exceptions is an unknown. Separating them prevents one confident sentence from masking four different kinds of evidence.
What this method cannot guarantee
- Classification is contextual: the same statement can move from assumption to fact when evidence arrives.
- The framework does not decide whether evidence is sufficient; reviewers must set that threshold.
- The method supports judgement; it does not transfer accountability from the people approving the decision.