Estimation Techniques in Agile #
Estimation in Agile is essential for planning and managing work efficiently. It helps the team understand the scope, complexity, and effort required for tasks, ensuring realistic planning and effective resource allocation. Here are some common estimation techniques used in Agile:
1. Planning Poker #
Planning Poker is a consensus-based estimation technique used to estimate the effort or relative size of user stories. Each team member selects a card with an estimate, and all cards are revealed simultaneously. If there is a significant difference in estimates, the team discusses and repeats the process until a consensus is reached.
– Steps:
– Product Owner presents a user story.
– Team discusses the story to ensure understanding.
– Each member selects a card representing their estimate.
– Cards are revealed simultaneously.
– Discussion occurs if estimates vary widely.
– Repeat until consensus is reached.
– Example:
– Story: “As a user, I want to reset my password so I can regain access to my account.”
– Estimates: 3 points, 5 points, 5 points, 8 points.
– Discussion reveals different assumptions about complexity.
– Consensus reached at 5 points.
2. T-Shirt Sizes #
T-Shirt Sizes is a relative estimation technique that categorizes user stories into sizes such as XS, S, M, L, XL based on their complexity and effort. This method is quick and useful for high-level estimation.
– Steps:
– Team discusses the user story.
– Team assigns a T-shirt size based on perceived effort.
– Sizes are relative and do not map to specific timeframes.
– Example:
– Story: “As an admin, I want to generate user activity reports.”
– Team assigns an “L” size due to the complexity of data aggregation and formatting.
3. Fibonacci Sequence #
The Fibonacci Sequence is used in Agile estimation to assign story points. It follows the sequence (1, 2, 3, 5, 8, 13, 21, …) where each number is the sum of the two preceding ones. This method reflects the uncertainty and complexity of larger tasks.
– Steps:
– Product Owner presents a user story.
– Team discusses the story.
– Each member selects a Fibonacci number as their estimate.
– Discussion and re-estimation occur if necessary.
– Example:
– Story: “As a user, I want to receive email notifications for account activity.”
– Initial estimates: 3, 5, 5, 8.
– Discussion refines understanding.
– Consensus reached at 5 points.
4. Three-Point Estimation #
Three-Point Estimation uses three values to estimate effort: the optimistic estimate (O), the pessimistic estimate (P), and the most likely estimate (M). The final estimate is calculated using the formula: Estimate = (O + 4M + P) / 6.
– Steps:
– Define the optimistic, pessimistic, and most likely estimates.
– Calculate the weighted average.
– Use the result as the estimate.
– Example:
– Story: “As a user, I want to update my profile information.”
– O: 2 hours, M: 4 hours, P: 6 hours.
– Estimate: (2 + 4*4 + 6) / 6 = 4 hours.
5. Bucket System #
The Bucket System is a group estimation technique where user stories are placed into “buckets” representing different sizes or efforts. The buckets are predefined categories, such as 1, 2, 3, 5, 8, 13, etc.
– Steps:
– Create buckets with predetermined values.
– Team places each user story into an appropriate bucket.
– Review and adjust if necessary.
– Example:
– Buckets: 1, 2, 3, 5, 8, 13.
– Story: “As a user, I want to add products to my wishlist.”
– Team places the story in the 5-point bucket after discussion.
6. Dot Voting #
Dot Voting is a quick and simple method where team members use dots or stickers to vote on estimates for user stories. The story with the most dots is assigned the corresponding estimate.
– Steps:
– Product Owner presents user stories.
– Team members vote on estimates using dots or stickers.
– The story is assigned the estimate with the most votes.
– Example:
– Story: “As a user, I want to filter products by category.”
– Votes: 2 dots on 3 points, 4 dots on 5 points, 1 dot on 8 points.
– Estimate: 5 points.
7. Affinity Estimation #
Affinity Estimation involves sorting user stories into groups based on their relative size or complexity, without using numbers initially. Once grouped, the stories are assigned point values.
– Steps:
– Team sorts stories into groups of similar size.
– Assign numerical values to each group.
– Review and adjust if necessary.
– Example:
– Stories are grouped into three categories: small, medium, large.
– Small = 2 points, Medium = 5 points, Large = 8 points.
– Assign point values to each story based on its group.
Conclusion #
Estimation techniques in Agile help teams plan and manage their work effectively by providing a structured approach to assessing effort and complexity. By using methods like Planning Poker, T-Shirt Sizes, Fibonacci Sequence, Three-Point Estimation, Bucket System, Dot Voting, and Affinity Estimation, teams can achieve better accuracy, improve collaboration, and make informed decisions. The choice of technique depends on the team’s preference, the nature of the work, and the context of the project.
