Assumption Log Template
A standard assumption and constraint log framework for tracking project uncertainties and boundaries.
§1 What is an Assumption Log?
An assumption log is a foundational project management artifact used to systematically record, track, and validate the conditions deemed true for the purpose of planning.
During the early phases of a project lifecycle, precise data is rarely available. To proceed with defining scope, budget, and scheduling, project managers must rely on assumptions (factors considered true without absolute proof) and constraints (fixed boundaries or limitations imposed on the programme). Because false assumptions often evolve into project risks, documenting them ensures transparency and assigns accountability for validation.
§2 The Core Template
The matrix below represents the standard structural columns required for a complete assumption and constraint log. When adopting this for your own organisation, ensure you retain the tracking columns (Actions, Status) as they distinguish a living document from a static list.
| ID | Category | Assumption / Constraint | Responsible Party | Due Date | Actions | Status | Comments |
|---|---|---|---|---|---|---|---|
| [A-01] | [e.g., Resources, Cost, Schedule] | [Clear, specific description of the assumption or constraint] | [Owner Name] | [Validation Deadline] | [Steps to verify the assumption] | [Open / Closed] | [Impact or context] |
§3 Quick Reference Guidelines
Use the following criteria when populating and managing your assumption log through the project lifecycle.
Categorise Consistently
Organise entries by impact area (Schedule, Budget, Scope, Quality, Stakeholders). This makes it easier to transfer unvalidated assumptions into your risk register.
Distinguish Constraints
Use a separate naming convention (e.g., C-01) for constraints. While assumptions are variables to be tested, constraints are hard boundaries dictated by business leadership.
Regular Maintenance
Centre this document in your routine project status meetings. An assumption log that is not updated at least fortnightly loses its value as a risk mitigation tool.