/pair-capability-estimate — Story Estimation

Apply the adopted estimation methodology to size a refined user story. Reads the estimation framework from guidelines and the adopted methodology from way-of-working.

Arguments

Argument	Required	Description
$story	Yes	Story ID to estimate. The story must be in Refined state with acceptance criteria.
$method	No	Override estimation method: complexity, time, ai-assisted, forecast, hybrid. If omitted, uses the adopted methodology from way-of-working.

Algorithm

Step 1: Load Story

1. Check: Read the story from the PM tool (per way-of-working.md).
2. Verify: Story exists and has acceptance criteria. If not refined → HALT: "Story must be refined before estimation."

Step 2: Check Existing Estimate

1. Check: Does the story already have an estimate (story points, hours, or sizing label)?

2. Skip: If no existing estimate, proceed to Step 3.

3. Act: Present the existing estimate:

   Story #$story already estimated: [estimate value] ([method used]). Re-estimate? (Only if explicitly requested by developer.)

4. Verify: If developer confirms current estimate → exit. If developer requests re-estimation → proceed to Step 3.

Step 3: Determine Estimation Method

1. Check: Is $method provided?
2. Skip: If provided, use it. Proceed to Step 4.
3. Act: Read way-of-working.md for the adopted estimation methodology.
4. Act: If no methodology adopted, read the Estimation Method Decision Matrix and recommend based on project context:
   • Team maturity, data availability, time pressure → select recommended primary method.
   • Present recommendation to developer for approval.
5. Verify: Method selected.

Step 4: Read Estimation Guidelines

1. Act: Read the methodology-specific guideline:
   • complexity → complexity-based-estimation.md
   • time → time-based-estimation.md
   • ai-assisted → ai-assisted-estimation.md
   • forecast → forecast-based-estimation.md
   • hybrid → hybrid-estimation.md
2. Verify: Guidelines loaded.

Step 5: Apply Estimation

1. Act: Analyze the story using the selected method:

   • Complexity-based: Evaluate story complexity against the team's reference stories. Assign story points using the adopted scale (e.g., Fibonacci: 1, 2, 3, 5, 8, 13, 21).
   • Time-based: Break story into tasks, estimate hours per task, sum with buffer. Consider skill level and availability.
   • AI-assisted: Analyze story description, AC, and technical analysis. Compare with similar completed stories. Propose estimate with confidence level.
   • Forecast-based: Use historical velocity and completion data to predict effort. Apply statistical model with confidence interval.
   • Hybrid: Apply multiple methods, compare results, converge on consensus estimate.

2. Act: Present the estimate to the developer:

   Estimation for #$story:

   Factor	Assessment
   Method	[method name]
   Estimate	[value + unit]
   Confidence	[High/Medium/Low — reason]
   Key Factors	[complexity drivers, risks, unknowns]

   Accept this estimate?

3. Verify: Developer approves. If developer disagrees → discuss and adjust.

Step 6: Record Estimate

1. Act: Update the story in the PM tool with the approved estimate.
2. Verify: Estimate recorded in the story.

Output Format

ESTIMATION COMPLETE:
├── Story:      [#ID: Title]
├── Method:     [complexity | time | ai-assisted | forecast | hybrid]
├── Estimate:   [value + unit (e.g., 5 SP, 20h, M(3))]
├── Confidence: [High | Medium | Low]
├── Rationale:  [key factors]
└── Status:     [Recorded | Confirmed existing]

Composition Interface

When composed by /pair-process-refine-story:

• Input: /pair-process-refine-story may invoke /pair-capability-estimate after AC and technical analysis are complete.
• Output: Returns the estimate value and method. /pair-process-refine-story includes the estimate in the story sizing section.

When invoked independently:

• Full interactive flow. Developer selects or confirms method, reviews and approves estimate.

Graceful Degradation

• If way-of-working.md does not specify an estimation methodology, use the Decision Matrix from the estimation guidelines to recommend one.
• If estimation guidelines are not found, fall back to developer judgment: ask the developer to provide an estimate directly and record it.
• If the PM tool is not accessible, present the estimate and ask the developer to record it manually.
• If the story has no acceptance criteria, warn: "Story lacks AC — estimation may be inaccurate. Consider refining first."

Notes

• This skill modifies the PM tool — it writes the estimate to the story issue.
• Idempotent: re-invocation on an already-estimated story confirms the existing estimate without re-doing the analysis. Re-estimation only happens on explicit developer request.
• The estimation method should be consistent within a project. If the team switches methods, record the decision via /pair-capability-record-decision.
• Estimation is a collaborative activity — the skill proposes, the developer decides. The skill never overrides developer judgment.