While both velocity and capacity are important concepts in Scrum, they represent different aspects of a team's ability to deliver work. Here's a breakdown of the key differences:
Velocity :
- What it is: A measure of the amount of work a team completes in a Sprint. It's typically expressed in story points, which are relative estimates of the effort required to complete a user story.
- Focus: Past performance. Velocity is calculated based on the team's historical performance in previous Sprints.
- Use: Sprint planning and forecasting. Velocity helps the team make realistic commitments for future Sprints and provides a basis for estimating project timelines.
- Example: If a team completed 30 story points in each of the last three Sprints, their average velocity is 30. This suggests they can likely complete around 30 story points in the next Sprint.
Capacity :
- What it is: A measure of the available effort a team has in a Sprint. It's typically expressed in person-hours, taking into account factors like team member availability, time off, and other commitments.
- Focus: Future availability. Capacity is an estimate of the total time the team has available for Sprint work in the upcoming Sprint.
- Use: Sprint planning. Capacity helps the team determine how much work they can realistically take on in the next Sprint, considering their available time and resources.
- Example: If a team has 5 members working 2 weeks Sprints with each member having 70 available hours, the total capacity is 700 hours.
Key Differences Summarized:
Relationship between Velocity and Capacity :
- Velocity informs Capacity: While capacity is about available effort, velocity provides a historical context for how much effort the team can realistically handle. A team with a higher velocity might have a higher capacity for work, assuming their availability remains consistent.
- Capacity constraints Velocity: Even if a team has a high velocity, their actual capacity in a given Sprint might be lower due to team member vacations, holidays, or other commitments. This would limit the amount of work they can realistically complete, affecting their actual velocity in that Sprint.
In essence :
- Velocity tells you how much work the team has done in the past.
- Capacity tells you how much effort the team will have available in the future.
By understanding the difference between velocity and capacity, Scrum teams can make more informed decisions during Sprint planning, ensuring they commit to a realistic amount of work and maximize their chances of achieving the Sprint Goal.
