SWEStash Effort Estimation
Produce honest, useful estimates without false precision. Estimates are forecasts, not commitments — always ranges, always improving as you learn more.
Workflow
Step 1: Ensure Tasks Are Defined
You can't estimate undefined work. Tasks must be broken down (use feature-planning
if not), have acceptance criteria, and have at least a sketched technical approach.
"I can't estimate this until we do a spike" is a valid and responsible answer.
Step 2: Choose the Method
T-shirt sizing for roadmap and early-stage sizing; story points (Fibonacci) for sprint planning and velocity tracking; three-point estimation for budget requests and high-uncertainty, high-stakes work; time-based only for well-understood tasks. See references/estimation-methods.md for detailed guidance on each method.
Step 3: Apply It
Estimate per task, not the project as a single unit; relative to known work rather than in absolute terms; as a team where possible (the familiarity gap between estimators reveals hidden complexity); with uncertainty explicit. Re-estimate when spikes complete or requirements clarify.
Step 4: Translate for Stakeholders
Convert to time or cost via team velocity or loaded cost, add a 20-30% buffer for unknowns, and communicate a range in stakeholder language — weeks and dollars, not story points. A single number becomes a commitment; a range communicates confidence.
Step 5: Track and Calibrate
Compare estimated vs actual each sprint, look for systematic bias, and recalibrate velocity on the last 3-5 sprints, not the all-time average.
Principles Applied
- KISS: Use the simplest estimation method appropriate. T-shirt sizing is fine for most roadmap decisions.
- Honesty over optimism: A realistic estimate that disappoints a stakeholder is better than an optimistic estimate that misses a deadline.
- YAGNI: Don't estimate items far in the future with precision. Estimate near-term work in detail, far-term work in ranges.