Story Points are a critical part of the Agile Framework, helping teams estimate the effort required to complete a user story or task. They reflect the complexity, uncertainty, and effort involved in implementing a feature or resolving an issue. Here's how you can ensure that story points are effectively assigned during Sprint Planning:
Story points are typically assigned based on a relative scale, where each story point value represents an estimate of the effort required to complete a task. The scale can vary depending on your team's preferences but commonly used scales include:
Fibonacci Sequence: 1, 2, 3, 5, 8, 13, 21
T-shirt Sizes: XS, S, M, L, XL
Story points are not directly tied to hours but reflect the relative complexity of tasks compared to each other.
Collaborative Estimation: Ensure that the whole development team participates in estimating the story points during sprint planning. This helps bring diverse perspectives, including those from developers, testers, and architects.
Shared Understanding: A task may look different from the perspective of a developer, a QA tester, or a business analyst, so itβs important to get input from all relevant roles.
Acceptance Criteria: For accurate story point assignments, make sure the acceptance criteria are clearly defined and understood. These criteria help to set expectations for what "done" looks like.
If the acceptance criteria are vague or unclear, the story's complexity is hard to estimate accurately.
Decompose Large Stories: If a user story is too big (epic), break it down into smaller, more manageable tasks that can be estimated more effectively.
Granularity: It's helpful to estimate stories that can be completed within a sprint, as stories that span multiple sprints can create uncertainty in point allocation.
There are a few popular techniques that your team can use to assign story points during sprint planning:
How it works: Each team member privately selects a card with their story point estimate. All cards are revealed at the same time. If estimates vary significantly, the team discusses the story until consensus is reached.
Benefit: This ensures that each team member has a voice and helps identify different perspectives on the storyβs complexity.
How it works: The team quickly sorts stories into categories (e.g., small, medium, large) based on their relative size and complexity.
Benefit: This is faster than detailed discussions and can be especially useful for stories that are easy to group.
How it works: Instead of assigning points, the team estimates stories using sizes like XS, S, M, L, XL. These sizes correspond to the relative complexity, but the exact point values can be defined later if needed.
Benefit: This can be helpful when you need a less granular, more abstract estimation.
How it works: Team members estimate the storyβs effort using three values:
Best Case: The minimum effort required if everything goes smoothly.
Worst Case: The maximum effort required if things go wrong.
Most Likely: The most realistic estimate based on current knowledge.
Benefit: This technique helps identify and mitigate risk by considering a range of outcomes.
Refer to Past Sprints: Compare the current story with similar stories from previous sprints to ensure consistency. If a task with similar complexity took X story points in the past, use that as a benchmark.
Review Completed Stories: At the end of each sprint, review how accurately the team estimated their story points. This helps refine future estimations and make them more accurate.
If a story is very uncertain or complex, itβs better to assign a higher number of points and then break the story down into smaller chunks in the next sprint or phase.
For example, if a story has ambiguous requirements, it might be safer to give it a higher point value to account for extra effort in clarification, meetings, or research.
Sometimes, stories require external systems or teams to perform actions outside of the immediate sprint's control (e.g., awaiting API from another team). These dependencies should be factored in when assigning story points, as they can add complexity.
If a team has not previously worked with a certain technology or domain, it's useful to assign a range of story points rather than a fixed value (e.g., "between 5 and 8 points"), indicating the uncertainty around that task.
As sprints progress, continuously evaluate the accuracy of story point assignments. If the team consistently underestimates or overestimates their points, adjust the process and re-align estimations.
If newer or junior developers struggle with assigning story points, consider running workshops or training sessions to improve their estimation skills. The better the team understands complexity, the more accurate the points will be.
Stay Consistent: Consistency is key to effective estimation. Make sure all team members use the same criteria for assigning story points.
Donβt Overthink It: Story point estimation is an approximation, not an exact science. Itβs about aligning the teamβs understanding and avoiding ambiguity.
Avoid Point Inflation: Resist the urge to assign more points than necessary, as this can cause issues with velocity measurement and sprint planning accuracy.