It might seem that software development and predictable results go together like fire and water – which is to say, not at all. Your developers might hit unexpected snags, productivity varies between Sprints, and it’s difficult to say how much exactly will be done, and when. But it doesn’t have to be that way; let’s explore how burndown charts, integral to agile project management, can help.
What is a Burndown Chart in Story Points?
A burndown chart is a graphical representation that shows the work completed versus the work remaining in a specific period, typically used within Agile and Scrum methodologies. The horizontal axis represents time (days, sprints, etc.), and the vertical axis represents the amount of work (hours, story points, etc.).
The ideal work remaining line is a straight line on the burndown chart that reflects a project’s overall scope, illustrating the progress expected if all tasks are completed on schedule. Burndown charts are essential tools for improving transparency and predictability in software development.
Sprint Burndown Charts with Ideal Work Remaining Line
Sprint Burndown charts lie in the first quadrant of the coordinate system. The x-axis represents days in the Sprint, and the y-axis expresses the summary of remaining hours or story points. Figures A and B are examples of Sprint burndown charts, where capacity is the summary of available developer hours in Sprint (this includes developers, QA, etc.).
A Sprint burndown chart enables work progress monitoring in a Sprint and product release by clearly visualizing the difference between the actual and predicted effort, often represented by the actual work line. The actual work line helps track the project's progress and indicates whether the project is ahead or behind schedule based on the accuracy of the team's time estimates.
The remaining effort is a crucial metric displayed on the y-axis, representing the effort needed to complete tasks quantified using story points. Comparing the remaining effort against ideal timelines aids in project management and informs stakeholders.
Burndown charts are useful in:
- Identifying delays in work,
- Daily work planning,
- Specifying team velocity,
- Planning of product release.
In Scrum, two types of burndown charts are commonly used:
- Sprint Burndown Chart
- Product Burndown Chart
The difference between them lies in the time range and ownership. The Development team uses a Sprint Burndown chart to monitor work progress within a single Sprint, whereas the Product Owner utilizes a Product Burndown chart for overall product management.
The Benefits of Sprint Burndown Charts
Planning and Organizing Work in the Sprint
With the knowledge about the ideal passage of time in the Sprint and the actual work remaining to finish tasks, it is possible to plan work. Tickets at risk are highlighted, and the team can decide to put in some additional effort to speed up these tasks or reorder the plan to ensure commitments are fulfilled.
Risk Monitoring
Based on the difference between the ideal time and remaining time, each day the chart shows how the actual work line fluctuates, indicating the risk of undelivered commitment.
Work Inspection
Sprint Burndown charts are also useful during the Sprint Retrospective. They answer many questions, such as:
- Why is no work progress visible between the 4th and 5th day of the Sprint?
- What happened when the estimation between the 3rd and 4th day of the Sprint was increased?
- What should we do in the future to avoid these situations?
Hours-based Sprint Burndown charts don’t show finished tasks. It is possible to have a small amount of hours left in the burndown chart while not delivering any story in the Sprint. That kind of situation often indicates the team is multitasking. For better visualization of how stories are delivered, it is recommended to use Story-points Burndown charts as described below.
Burndown chart B shows the relation between team capacity and story points committed to the Sprint and allows monitoring of work progress in the Sprint. Similar to example A, daily updates are required. The team checks which tasks have been delivered already and subtracts delivered story points from the story points committed to the Sprint.
Considering the benefits of the two mentioned types of burndown charts, it makes sense to use both in parallel. The Story-points Burndown chart provides an overview of task completion, while the actual work remaining line offers real-time progress tracking, reflecting the actual performance and helping teams monitor whether they are on schedule or falling behind.
Product Burndown charts (a.k.a. Release Burndown charts)
A Product Burndown chart operates in the first and fourth quadrants of the coordinate system. The x-axis represents the Sprint number, and the y-axis represents a summary of all story points of all items in the Product Backlog. The figure below is an example of the Product burndown chart.
Note: Information about the burndown charts usage in the fourth quadrant of the coordinate system is advanced knowledge and will be described in future articles.
The Product Burndown chart is updated after each Sprint by the Product Owner. To create and use a Product Burndown chart, you should evaluate all items in the Product Backlog. After each Sprint Review, the Product Owner subtracts story points achieved in the last Sprint from the summary of all story points in the Product Backlog and updates the chart.
Example of Product Burndown Chart
- Summary of all story points at the beginning of the project = 400
- Result of Sprint 1 = delivered 100 SP (Story points); remaining = 300 SP
- Result of Sprint 2 = delivered 53 SP; remaining = 247 SP
The Benefits of Using Product Burndown Charts
Project & Sprint Planning
With the knowledge of the total number of story point estimates and the average velocity of story points delivered by the Development team, it is possible to predict and plan when functionality can be released.
Risk Monitoring
Comparing the release plan with the actual work done, the Product Owner monitors the work remaining line to identify delays, assess the risk of under-delivery, and communicate with the client to minimize the cost of delays.
Work Inspection
During the Sprint Review, the whole Scrum team and all stakeholders can analyze the chart and forecasts, see the risk, and plan future actions.
Final Thoughts on Burndown Charts in Agile Project Management
Burndown charts are invaluable tools for enhancing transparency and predictability in software development, especially in agile projects. By regularly using Sprint and Product Burndown charts, teams managing agile projects can better plan, monitor risks, and inspect work progress. These charts help track progress, identify potential issues such as scope creep, and maintain communication among team members. Smartly use them and adjust them to your project’s needs.
What’s your experience with burndown charts? Any stories or tips you might want to share? Don’t hesitate to drop us a comment or a question here.
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