EP-03
Story Points vs Time Spent — Calibration Drift
Estimation Precision
Default severity: medium
EstimationQualityBusiness ValueEffort
What it detects
The relationship between story points and actual time spent has drifted significantly between the current period and the baseline period — the team\'s SP calibration has changed, making velocity comparisons across periods invalid. baseline_hrs_per_sp = AVG(time_spent / story_points,
Detection formula
period=config.ep.baseline_period) current_hrs_per_sp = AVG(time_spent / story_points, period=config.ep.current_period) drift_pct = ABS(current_hrs_per_sp - baseline_hrs_per_sp) / baseline_hrs_per_sp IF drift_pct > config.ep.calibration_drift_threshold // default: 30% THEN FLAG calibration_drift IF drift_pct > config.ep.critical_calibration_drift // default: 60% THEN CRITICAL — velocity comparisons across periods are misleadingExamples in practice
- A team shows the relationship between story points and actual time spent has drifted significantly between the current period and the baseline period while baseline period is set to Configured per workspace.
- Example signal: The relationship between story points and actual time spent has drifted significantly between the current period and the baseline period — the team\'s SP calibration has changed, making velocity comparisons across periods invalid.
Suggested response
Recalibrate estimation precision—check size classes, drift, and BV vs effort trade-offs.
Coaching playbook
Symptom
The relationship between story points and actual time spent has drifted significantly between the current period and the baseline period — the team\'s SP calibration has changed, making velocity comparisons across periods invalid. baseline_hrs_per_sp = AVG(time_spent / story_points,
Why it matters
When "Story Points vs Time Spent — Calibration Drift" keeps appearing, the team is signalling a repeatable process gap. Left unexamined, the pattern hides where work really stalls and makes improvement metrics harder to trust.
What you can achieve
Recalibrate estimation precision—check size classes, drift, and BV vs effort trade-offs.
Facilitation questions
- What system change would stop "Story Points vs Time Spent — Calibration Drift" from firing again?
- What do the cited issues have in common — same root cause or same workaround?
- Who owns the two-week experiment and how will we verify on the next import?
Run this rule against your own tracker data with Flow Analyzer.