Sprint Velocity After Team Changes
How to handle velocity when team members join or leave. Covers re-baselining, the Tuckman model, and setting expectations during transitions.
Detailed Explanation
Velocity and Team Changes
When a team member leaves or joins, velocity is affected. Understanding the pattern helps set realistic expectations during transitions.
The Tuckman Effect
Teams go through stages: Forming, Storming, Norming, Performing. Any roster change resets the team partially.
Velocity timeline after adding 1 person to a 5-person team:
Sprint 1-2 (Forming): Velocity drops 15-25%
Sprint 3-4 (Storming): Velocity returns to ~90% of previous
Sprint 5-6 (Norming): Velocity stabilizes at new baseline
Sprint 7+ (Performing): Velocity may exceed previous baseline
When Someone Leaves
The impact depends on the person's role and knowledge:
Key contributor leaves: 30-40% temporary velocity drop
Average contributor leaves: 15-20% temporary velocity drop
Recovery time: 3-5 sprints
When Someone Joins
New members initially reduce velocity because existing members spend time onboarding:
Sprint 0: New member joins, velocity drops ~20%
Sprint 1-2: New member contributes 20-40% of team average
Sprint 3-4: New member contributes 60-80% of team average
Sprint 5+: New member reaches full capacity
How to Handle Velocity During Transitions
- Communicate the expected dip to stakeholders before it happens.
- Reset the velocity baseline -- discard old data after major changes (2+ people on a 5-person team).
- Reduce sprint commitments by 20-30% for the first 2-3 sprints.
- Track the new velocity separately until it stabilizes.
Key Insight
Velocity is a property of the team as a whole, not the sum of individual capacities. Changing one person changes the dynamics of the entire team.
Use Case
Use this guide when planning around team changes, communicating expected velocity dips to management, or onboarding new team members into an existing Scrum team.