Story points are one of the best things to happen to agile teams. I’ve personally experienced how they completely change project estimation. Unlike time estimates, They account for complexity, effort, and uncertainty. As a result, you can make more accurate predictions and execute projects more smoothly. You’ll also likely notice a significant improvement in your team’s productivity and planning workflow.
What Are Story Points in Agile?
They are a unit of measure in Agile project management that represents an estimate of the effort required to complete a user story or task. It’s a combination of the story’s complexity, effort and risk/uncertainty. Story points are a relative measure of size and difficulty, as opposed to time-based estimates.
I’ve personally found story points to be a valuable concept throughout my 15+ years of experience in software development. Instead of focusing on detailed time estimates, They allow teams to concentrate on the scope of work. This change in mindset often results in more accurate planning and better collaboration among the team.
Story points have several key advantages:
- More accurate estimates: Teams that use them are 43% more accurate in their estimates than teams that use time-based estimates.
- Flexibility: They help account for different skill levels and work styles among team members.
- Value-based discussion: Shifting from hours to story points helps teams talk more about the relative value and complexity of items in the backlog.
- A standard unit of measurement: They create a standard unit of measurement for various types of work.
- Less pressure: Story points eliminate the pressure to commit to specific hours.
As a result of my experience managing more flexible development processes, I’ve seen story point estimates become the standard in 60% of Agile teams. The widespread adoption of them speaks to the benefits of the more accurate project planning and execution that they provide.
Story points encourage you and your team to think about the work more holistically. It’s not just about time. It’s about complexity, risk and the overall effort. This shift in thinking often leads to more realistic expectations and smoother project delivery.
Story Point Scales and Estimation Techniques
The Fibonacci sequence is the most common story point scale. That sequence (1, 2, 3, 5, 8, 13, 20, 40, 100) is the foundation of most story point scales, and it’s the scale I’ve personally used with great success throughout my career managing software projects.
The reason the Fibonacci sequence works so well is that it accounts for tasks becoming exponentially more uncertain as they get larger. As you increase the numbers, the gaps between them grow larger, which is an accurate reflection of our ability as humans to estimate them less accurately as tasks become more complex or take more time.
You might be wondering why we can’t use a linear scale. The key lies in the principle of relative sizing. In Agile, the objective isn’t to accurately estimate the hours of work to complete the project. Instead, it’s to relatively compare the size and complexity of one task to another.
Here’s how you can use story point estimation:
Select a baseline story: Choose a simple, well defineable task and give it a point value (usually 1 or 2).
Compare other stories: Use your selected baseline story to estimate the points of additional stories.
Planning poker: Planning Poker is a popular technique used to estimate story points. Each team member independently selects a story point value, and then you discuss to reach a consensus story point value.
- Getting everyone to agree: Discuss any large discrepancies among estimates so everyone has a shared understanding of how many points each story is.
Planning poker has revolutionized my experience using them. It ensures everyone has a say, and as a result, the estimates are much more accurate. Additionally, discussing different perspectives often reveals hidden complexities or risks within the story.
Remember, the goal of using them isn’t 100% accuracy. Instead, the goal is to ensure everyone has a shared understanding, and you’ll continue to get better at estimating story points over time.
Implementing Story Points in Sprint Planning
Introducing story points to your team can have a material impact on your sprint planning. I’ve personally seen planning meeting times reduced by as much as 40% after effectively introducing them to the sprint planning process.
Here’s how to step-by-step introduce story points to your sprint planning:
- Educate your team: Make sure everyone understands story points and the value of using them.
- Try a trial run: Use Them in addition to your current estimating strategy for one or two sprints.
- Estimate: Hold estimation meetings separate from sprint planning.
- Use story point estimates in sprint planning: Base your sprint capacity on past velocity.
- Review and adjust: Evaluate how accurate your estimates were following each sprint, and adjust accordingly.
Your estimates will likely be inaccurate the first time you use them – don’t worry, this is normal. You can expect planning meeting times to improve by 20-30% within the first few sprint planning sessions of using story points.
During sprint planning, focus exclusively on the points the team can complete based on past performance. Remember, using story points as capacity results in less rigidity than planning based on hours. You’re not assigning specific hours to each task, which means the team can self-organize on how to achieve the goal.
Keep track of your estimated story points and the actual outcomes over time. This data will allow you to refine the approach and improve accuracy. You’ll often find consistent themes where certain types of work are always over or under estimated.
Ultimately, story points are rarely accurate to the point. They help create a shared understanding of the work and improve your team’s ability to reliably plan and deliver.
Understanding and Using Velocity
Velocity is one of the key metrics in Agile project management. It’s a measure of how much work a team can accomplish in a single sprint, which is measured in story points. If you know how to calculate and use velocity, it can dramatically improve your sprint planning and release projections.
Here’s how to calculate and use velocity:
- Track completed : At the end of each sprint, add up the story points for all items that the team has fully completed.
- Calculate average velocity: After several sprints, take the average of completed story points to determine your team’s velocity.
- Use it in sprint planning: Plan your future sprints based on the team’s average velocity.
- Forecast releases: Estimate when larger projects will be completed based on velocity.
In my experience, velocity tends to stabilize after about 3-4 sprints. Although, many teams don’t reach truly stable velocity until after 4-6 sprints. Stability is the point at which you can start making more accurate long-term plans.
A number of different factors can impact how quickly velocity stabilizes:
- Team changes
- Process changes
- External dependencies
- Variable sprint lengths
Don’t panic if your velocity bounces around. It inherently reflects the variability of project work. Instead, look for overall trends, rather than scrutinizing over whether velocity was up or down by one point from one sprint to the next.
You can make more accurate, data-driven decisions about the timeline of a project and the team’s capacity by understanding velocity. For instance, if you add up all the points in the backlog and velocity is 20 story points per sprint, you can forecast that the project will be completed in 5 sprints.
Remember, velocity is a descriptive metric, not a prescriptive metric. Meaning, use it as a way to improve your planning, rather than using it as a baseball bat to try to increase velocity at all costs.
Best Practices for Story Point Estimation
Successfully implementing a story point system requires careful planning and execution. In my experience managing software teams, it usually takes teams 2-3 sprints to fully adopt a story points system. However, the upfront investment of time is well worth it. Teams that have undergone formal story point training are 35% more likely to be successful with Agile.
Here are some of the best practices to improve your story point estimates:
Full Training: Make sure all of your team members understand the benefits of using them.
Clear Baseline: Select a user story that everyone on the team understands really well, and use it as your baseline for all estimates.
Relative Sizing: Always make estimates relative to other user stories, not absolute.
Whole Team Involvement: Always make story point estimates as a team including developers, testers, and anyone else who will work on the user story.
Regularly re-calibrate your scale: Retrospect on your estimates and adjust your scale as needed to keep it accurate.
Don’t compare between teams: Avoid using to compare productivity between teams.
Don’t convert points to hours: Don’t make the mistake of creating a conversion rate from points to hours. This defeats the purpose.
Consistency over accuracy: It’s more important that your team is consistent with their estimates than accurate.
One common mistake I see teams make when adopting story points is trying to be too precise. Keep in mind that the goal of them is not to be precise. It’s just to roughly measure relative size.
Another mistake is changing the scale of your story points in the middle of a project. This will make your velocity measurements inaccurate, making planning more challenging. If you do need to adjust it, make sure it’s at a clear break point in the project, such as the start of a new release.
By following these best practices, your team will be well positioned to be successful with story point estimates. The key is to think of it as another tool to help your team understand and plan their work (not a strict measure of productivity or performance).
Improving Accuracy and Consistency in Story Points
Improving your ability to estimate story points accurately is a journey. From my experience, story point accuracy usually increases by about 25% after the first 6 sprints. This improvement primarily comes from people understanding the system better and applying estimation techniques more consistently.
Here are some of the strategies you can use to improve your team’s estimation skills:
Retrospectives: Spend time in sprint retrospectives talking about the accuracy of estimates.
Track and analyze trends: Record your estimates versus actual for delivered work.
Re-estimate stories that weren’t completed: If you fail to finish a story within a sprint, re-estimate the story before planning it into the next sprint.
Handle outliers: If you have a story that’s significantly larger than any other story, consider breaking that one story down into smaller stories.
Use historical data: Compare new work to similar stories you’ve completed in the past.
Fostering a team of people talking: Create a culture of people talking and challenging each other’s estimates.
Dealing with edge cases is difficult. For example, a story might be about a new feature, and the story feels simple. However, with our current understanding of the system, you are not sure what the implementation will look like. In our business, it’s common to add an “uncertainty factor” to these stories.
To measure this, you should measure the difference between what you estimated and the actual number of story points you completed over time. As you improve, the difference should become smaller over time. However, it will never be zero. The key is that it’s less than whatever it was in the past.
Remember, doing this really is a team effort. You want people to feel comfortable talking about and learning from both wins and mistakes. Over time, you will find that your team gets better at estimating, leading to better sprint planning and more predictable delivery.
Challenges and Misconceptions About Story Points
Story points, though effective, are often misinterpreted. In my experience with Agile implementations, I’ve seen several common challenges and misconceptions.
One common challenge is using them as a direct conversion to hours. This defeats the purpose of them, as they’re supposed to be a relative effort, not time.
Another challenge is pushback from team members who have always used hourly estimates. They might feel that story points are too abstract or it’s hard to get everyone to agree on the number. You can solve for this by educating the team on why they are valuable and demonstrating how they work.
You may also feel pressure to use story points as a performance metric. Avoid this temptation. Story points are a planning tool, not a productivity measurement.
Balancing them with other Agile metrics is key. While they are useful, they shouldn’t be the only metric you consider. Look at your story points in conjunction with other metrics like sprint burndown, cycle time, or customer satisfaction.
To ensure you can use them effectively, remember the following:
- They need to be team specific.
- They are are for estimation, not evaluation.
- Consistency matters more than accuracy.
- They are not a silver bullet to replace other Agile practices.
By understanding these challenges and getting ahead of them, you can successfully use them and enjoy the benefits of story points in your Agile projects.
It’s worth noting that story points are just one of many agile tools that can improve your project workflow. When used in conjunction with other Agile methodologies and practices, they can significantly enhance your team’s efficiency and project outcomes.
To Conclude
Story points have transformed Agile development. They improve estimation accuracy, offer a common language for teams, and make sprint planning more efficient. It takes time and practice to learn how to use them effectively. Most teams see major results after 4-6 sprints. Keep in mind that estimation is a continuous journey. Refine your strategy through retrospectives and data after every sprint. With a little persistence,
