Top 9 Agile Estimation Techniques That You Must Know

Story Points

Story points are a popular agile estimation technique to estimate the size or complexity of a task rather than the time it will take. Teams assign points to tasks based on how difficult or time-consuming they seem. For example:

• Easy tasks might get 1-3 points.
• Medium tasks could get 5-8 points.
• Challenging tasks get 13 or more points.

Choosing the proper agile estimation techniques is crucial for accurately assessing the effort and resources needed for tasks in a prioritized backlog.

Story points help teams focus on effort rather than exact hours, making estimation less stressful and more flexible. This technique also accounts for the uncertainty in estimating work and allows teams to adapt to changing priorities.

Dot Voting

Dot voting is a quick and relatively straightforward method where team members use dots (stickers or markers) to vote on tasks they think are most important or challenging. Each person gets a certain number of dots to allocate.

This technique works well for prioritizing tasks and getting everyone’s input. For example, a team can use dot voting in a sprint planning meeting to decide which user stories to tackle first.

Affinity Mapping

Affinity mapping groups similar-sized or complex tasks into jobs. Teams start by writing tasks on sticky notes and placing them on a board. Then, they arrange the notes into groups based on their similarities. This method helps you see how to do things and find patterns.

Affinity mapping encourages team collaboration and helps uncover dependencies between tasks. It’s beneficial when dealing with large backlogs or complex projects.

Comparative Estimation

Comparative estimation involves comparing tasks to each other instead of estimating them individually. For instance, teams might say, “Task A is about the same size as Task B but smaller than Task C.” This technique is excellent for quickly estimating multiple tasks.

Comparative estimating uses relative estimation and relative effort to decrease the stress of assigning absolute values to jobs. This method helps with sprint planning and backlog refinement.

Three-point method

The three-point technique estimates task effort using only three possible values and values:

• Optimistic: The best-case scenario.
• Pessimistic: The worst-case scenario.
• Most likely: The average or expected effort.

Teams then average these three values for a reasonable estimation. This method provides a balanced view by considering uncertainties and potential risks, making it ideal for complex projects.

Bucket System Estimation Technique

The bucket system groups tasks by size or complexity. Buckets might be labeled “small,” “medium,” “large,” etc. Team members discuss and agree on where each task fits, making it a collaborative and visual method.

This technique works well for remote teams, as it can be easily adapted for online tools like virtual whiteboards or project management software.

Planning Poker

Planning poker makes task estimation entertaining and participatory. Each team member has a set of cards with numbers (e.g., 1, 2, 3, 5, 8). The four team members discuss a job, and each person picks a card showing how long it will take.

If the figures are different, each team member explains why they think that way until everyone agrees. Planning poker fosters open communication and in-depth mutual understanding and ensures all team members’ opinions are considered. It’s particularly effective for building consensus in cross-functional teams.

T-shirt Sizing

T-shirt sizing is a simple method for categorizing tasks into sizes like XS, S, M, L, or XL. This approach is easy to understand and works well for teams new to Agile.

For example, a team might categorize a minor bug fix as “S” and a significant feature development as “XL.” T-shirt sizing provides a quick way to prioritize tasks without diving into detailed discussions.

Big, Uncertain, Small

This agile methodology helps teams prioritize tasks and identify areas that need further exploration. It’s a great starting point for breaking down large projects into manageable pieces. In this technique, tasks are grouped into three categories:

• Big: Tasks that are very large and complex.
• Uncertain: Tasks that require more information or clarity.
• Small: Tasks that are simple and quick to complete.

Ambiguous Requirements

While Agile is designed to accommodate evolving project scopes, the initial lack of detailed requirements often makes estimation challenging. Without concrete details, teams rely on assumptions, leading to under- or overestimating tasks.

For example, when building a feature, developers may not know how users will interact with it or whether stakeholders’ goals might shift during development.

Solution: Encourage regular communication between stakeholders and the development team to refine requirements and validate assumptions early in the process.

Rapidly Changing Environments

Agile projects thrive in dynamic industries such as software and technology. These sectors are prone to frequent updates in user needs, market demands, or compliance requirements. Estimating timelines for large and complex tasks in such environments requires extra foresight and flexibility.

Solution: Incorporate iterative planning and conduct frequent backlog sessions to accommodate evolving changes effectively.

Variability in Team Expertise

An Agile team often comprises members with diverse skill levels and experiences. A highly skilled developer may estimate a task to be five hours, whereas a less experienced member might need twice as long for the same task. Teams must consider these variations to produce realistic estimates.

Solution: Use pair programming or mentorship opportunities to balance expertise and refine estimations based on collective input.

Complexity of Interdependencies

Agile projects sometimes involve multiple teams working on important features. A delay in one team’s deliverable can cascade into other tasks, disrupting initial estimations. For example, if one team’s backend API isn’t ready on time, the frontend team’s sprint goals could be affected.

Solution: Map dependencies during sprint planning and create contingency plans to minimize cascading delays.

Balancing Accuracy with Agility

While precision is desirable, Agile prioritizes adaptability. Teams can’t spend excessive time perfecting estimates, as the primary goal is quickly delivering working increments. Striking this balance is a common hurdle.

Solution: Use range-based estimation (e.g., optimistic, realistic, and pessimistic scenarios) to balance accuracy and flexibility.

Human Biases

Humans naturally have biases that can affect estimation accuracy. For instance, optimism bias might lead a team to underestimate task complexity and achieve perfect accuracy. At the same time, anchoring bias could result in sticking too closely to previous estimates without fully considering new challenges.

Solution: Conduct estimation sessions with diverse team members and encourage critical discussions to mitigate biases.

Dependence on External Factors

Projects commonly use third-party tools, libraries, and providers. A delay or unforeseen issue with an external component can disrupt timelines, making initial estimates unreliable. Teams must account for these risks when making projections.

Solution: Include risk assessment and buffer time in your estimations for potential external delays.