# Capacity Honesty — the numbers teams lie to themselves about

Sprint commitments fail for predictable, countable reasons. This is the checklist of capacity leaks to price in *before* committing, not discover after.

## The leak table

| Leak | Typical size | The honest correction |
|---|---|---|
| **Carry-over** | 10-30% of velocity | Unfinished stories re-enter at REMAINING size, and they come first — new work fits in what's left |
| **Meetings & ceremonies** | 15-20% of hours | Compute person-days from *focus* days, not calendar days |
| **On-call / interrupts** | one person ≈ 50% | The on-call engineer contributes half, or zero for a hot service — decide which and write it |
| **Leave & holidays** | obvious yet skipped | Subtract per person; a 10-day sprint with 2 people out 3 days each lost 12% before it began |
| **The unplanned-work tax** | 10-25%, team-specific | Look at the last 3 sprints: what % of completed points were unplanned entries? That tax recurs; budget it |
| **New-joiner drag** | joiner at 30-50%, mentor −20% | Ramping is real work; pretending otherwise burns both people |

## The 80% rule, applied correctly

Commit to ~80% of *corrected* capacity, not raw velocity. The 20% isn't slack for laziness — it's the measured cost of the leaks you couldn't itemise. Teams that commit at 100% don't go faster; they carry over more and demoralise sooner.

## Velocity hygiene

- Use the **median of the last 3-6 sprints**, not the best sprint or the mean (one heroic sprint poisons a mean)
- Velocity after a team change is a NEW series — 2 sprints minimum before trusting it again
- If velocity is "improving" while carry-over grows, it isn't improving — points are inflating

## The commitment conversation

When the corrected number disappoints stakeholders, the answer is scope, never arithmetic: "we can commit to A and B, or A and C — which?" Teams that negotiate the math instead of the scope are scheduling their own failure retro.
