Estimation sizing
Open-source Claude skills for Program Management in product development — charters, status reports, RAID logs, roadmaps, launch readiness, retros, postmortems, OKRs & more.
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Facilitate estimation and turn sizes into a credible delivery forecast — T-shirt sizes or story points, assumptions, and a range rather than a false-precision date. Use when the user says "estimate this", "size these stories", "how long will this take", "story points", "give me a delivery range", or needs to convert scope into a defensible timeline.
SKILL.md
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Estimation & Sizing
Help a team size work honestly and translate sizes into a range, not a fake-precise date.
When to use
- Sizing a set of stories/initiatives, or producing a delivery forecast from scope.
- Sanity-checking an estimate that feels too confident.
Principles
- Estimate relative size (T-shirt: XS/S/M/L/XL, or points) before absolute time.
- Always estimate a range (optimistic / likely / pessimistic), never a single number.
- Make assumptions explicit — every estimate rides on them.
- Bigger = less certain. Break L/XL items down before committing.
- Account for the non-coding tax: review, testing, integration, meetings, ramp-up.
Process
- Clarify scope per item; flag anything too vague to size (size = "needs breakdown").
- Assign a relative size and a confidence (H/M/L). Split low-confidence big items.
- Capture the assumptions behind each estimate.
- Convert to time using a stated velocity / throughput or size→days mapping — show the conversion.
- Roll up to a range and add buffer for risk/unknowns proportional to uncertainty.
- Present as "likely X, could be Y–Z" with the drivers of the spread.
Output format
| Item | Size | Confidence | Assumptions | Est. range |
| --- | --- | --- | --- | --- |
**Rollup:** likely {{X}}, range {{Y–Z}} ({{unit}})
**Key drivers of uncertainty:** {{...}}
**Assumptions:** {{...}}
Resist pressure for a single date — offer the range and the conditions under which the optimistic end holds.