Template
Turn an assumption into a named temporary requirement state
An unlabeled assumption quietly becomes a permanent fact.
When it fits
- A requirement contains an unknown value or premise that everyone knows is provisional but nobody owns resolving.
When to avoid it
- Not all uncertainty should block progress. The point is to expose and manage it, not wait for perfect knowledge.
A template to use
Temporary assumption: [ ]. Rationale: [ ]. Risk if wrong: [ ]. Owner: [ ]. Resolve by: [ ]. Evidence needed: [ ].
Why it matters
Record the best current assumption, why it is being used, the risk if wrong, who must resolve it, by when and what evidence will close it. Keep provisional values visibly provisional rather than hiding them in normal requirement text.
An example
A migration design assumes a maximum daily volume based on incomplete history; the data owner is assigned to confirm it before load-test sizing is frozen.
Check your result
Every consequential provisional premise has an owner and closure condition.
Keep this limit in mind
- Not all uncertainty should block progress. The point is to expose and manage it, not wait for perfect knowledge.
Connected ideas
Useful withTrace every costly requirement back to the need it protects
Evidence and sources
NASA guidance recommends requirements that identify the responsible product or party and needed behavior, use consistent terminology, state what is needed rather than prescribing implementation, and include rationale and assumptions.
Some constraints legitimately specify implementation when mandated by architecture, regulation or compatibility.
Appendix C: How to Write a Good Requirement · Editorial checklist; general goodness checklist
NASA's requirements checklist emphasizes clarity, one thought per requirement, completeness, explicit assumptions, consistency, traceability, feasibility and verifiability.
The checklist is for systems engineering; smaller tasks can apply the principles proportionally.
Appendix C: How to Write a Good Requirement · Requirements validation checklist