Estimating Work
estimating-work
Estimate effort for development tasks. Use when planning sprints, roadmaps, or project timelines. Covers story points, relative estimation, and uncertainty.
SKILL.md
Full skill instructions
Estimating Work
Estimation Approaches
Story Points
Relative complexity, not time.
| Points | Complexity |
|---|---|
| 1 | Trivial, well understood |
| 2 | Simple, minor unknowns |
| 3 | Moderate complexity |
| 5 | Complex, some unknowns |
| 8 | Very complex, significant unknowns |
| 13 | Extremely complex, many unknowns |
| 21+ | Too big, needs decomposition |
T-Shirt Sizing
For high-level estimates.
| Size | Relative Effort |
|---|---|
| XS | Hours |
| S | 1-2 days |
| M | 3-5 days |
| L | 1-2 weeks |
| XL | 2-4 weeks |
Estimation Factors
Consider:
- Complexity: How difficult is the problem?
- Uncertainty: How much is unknown?
- Effort: How much work is involved?
- Risk: What could go wrong?
Estimation Techniques
Planning Poker
- Present the task
- Everyone selects estimate privately
- Reveal simultaneously
- Discuss outliers
- Re-estimate if needed
Three-Point Estimation
Expected = (Optimistic + 4×Likely + Pessimistic) / 6
Reference Stories
Keep calibration stories:
- "This 3-point story took 2 days"
- "This 8-point story took a week"
Common Pitfalls
- Anchoring: First estimate biases others
- Optimism: Underestimating unknowns
- Scope Creep: Original estimate doesn't match final scope
- Ignoring Overhead: Code review, testing, deployment
Tips
- Estimate in ranges, not points
- Include buffer for unknowns
- Track actual vs. estimated
- Re-estimate when scope changes
- Don't estimate in hours (use relative sizing)