Story Points
Story points are a unit of measure for expressing the overall effort, complexity, and uncertainty involved in completing a Product Backlog item, used for relative estimation rather than measuring time.
Explanation
Story points represent relative sizing. Rather than estimating how many hours a task will take, the team compares items against each other to determine relative complexity. A story estimated at 5 points is roughly two-and-a-half times the effort of a 2-point story. Common scales include the Fibonacci sequence (1, 2, 3, 5, 8, 13, 21) and T-shirt sizes (XS, S, M, L, XL).
The value of story points lies in their abstraction. Different team members may work at different speeds, but they generally agree on relative complexity. Over time, a team's velocity (the number of story points completed per sprint) becomes a reliable predictor of how much work the team can take on in future sprints.
Story points are estimated by the Developers, not by the Product Owner or management. Techniques like Planning Poker are commonly used for collaborative estimation. The key is that the team reaches consensus on relative size.
Key Points
- •Measure relative effort, complexity, and uncertainty rather than time
- •Common scales: Fibonacci sequence or T-shirt sizes
- •Estimated by the Developers through collaborative techniques
- •Used to calculate team velocity and forecast future capacity
Exam Tip
Story points measure relative effort, not absolute time. If an exam question converts story points directly to hours, that approach is incorrect.
Frequently Asked Questions
Related Topics
Velocity
Velocity is the amount of work a Scrum team completes in a Sprint, typically measured in story points, used to forecast how much work the team can handle in future sprints.
Planning Poker
Planning Poker is a consensus-based agile estimation technique where team members privately select cards representing their estimate, reveal them simultaneously, and discuss differences to reach agreement.
Relative Estimation
Relative Estimation is an agile technique where work items are sized in comparison to each other rather than in absolute units like hours or days, providing faster and more accurate estimates.
User Stories
A User Story is a short, informal description of a feature told from the perspective of the person who desires the new capability, typically following the format: As a [role], I want [goal], so that [benefit].
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