Assumption Log
A project document that captures, tracks, and updates all assumptions and constraints from project start through closure.
Key Points
- It is a living document, updated whenever new assumptions or constraints are identified, validated, or disproved.
- Entries typically include description, source/owner, date, potential impact, status, and any required actions.
- It feeds risk management; invalid or uncertain assumptions can become risks or issues requiring responses.
- Reviewed in governance and change control to understand effects on scope, schedule, cost, and quality.
Example
On a software project, the team assumes the vendor API will be available by May 1, and notes a constraint that the budget cannot exceed USD 500,000. The project manager records both in the assumption log, assigns owners to validate the API date and monitor budget caps, and updates the log when the vendor confirms a June release, triggering a schedule risk and mitigation actions.
PMP Example Question
During planning, the project manager documents a belief that a supplier can deliver components by month-end without formal confirmation and notes a fixed funding cap set by the sponsor. Which document should be updated?
- Risk register
- Cost baseline
- Assumption log
- Procurement management plan
Correct Answer: C — Assumption log
Explanation: Assumptions and constraints are recorded and maintained in the assumption log. The risk register captures identified risks, while the cost baseline and procurement plan serve different purposes.
