Sprint Burndown Chart

Burndown charts today have become more popular in providing stakeholders as well as the team members the status whether a sprint goal is accomplished in an easy, understandable way or not.

What is a sprint burndown chart?

Sprint burndown is a graphical representation of the estimated effort-hours remaining for a given period of time during a Sprint. Plotting the total effort-hours remaining for each incomplete task on a given day, on a graph, results in the sprint burndown chart which is significant for communicating progress as shown below.
The horizontal axis of the sprint burndown chart represents the days within a sprint, whereas the vertical axis represents the remaining estimated effort-hours. The chart should be updated every day to exhibit the total estimated effort remaining across all the uncompleted tasks.

Why Sprint burndown chart?

It makes the teamwork visible. As the team is responsible for self-directing, self-managing, and self-organizing themselves to achieve greater success, the sprint burndown chart helps them to ‘see where they are’.

Sometimes, the team might not be able to specify the complete set of tasks required to design, build, integrate, and test the intended product backlog items. So, they can add new tasks corresponding to the intended product backlog items at any time to the sprint backlog. For instance, if on day 3 the team found that task 6 was missing, it can be added. There is no need to avoid a task from being added to the sprint backlog. As the understanding of the work enhances by doing it, the team can adjust the sprint backlog. This is where the sprint burndown chart comes into the picture which shows the team the work that needs to be done to complete a product backlog item that they promised to get done.

In simple words, we can say sprint burndown charts are helpful to track the amount of work remaining in a sprint backlog, see how quickly the team has finished the tasks, and predict when the team will reach the sprint goals.

Who all are involved in sprint burndown chart?

The following individuals will be involved in Sprint burndown chart:

• Developers (the team)
• Product Owner and
• Scrum Master

The team is responsible for making the ‘work in progress’ transparent to the stakeholders. The Product Owner decides whether the release plan needs to be updated or the project is on schedule. The Scrum Master supports, coaches, and reminds individuals of the rules underlying Agile software development.

When do we use this sprint burndown chart?

The team members use it religiously during sprint execution to report the estimated effort remaining for each uncompleted task. Because, each day during the sprint the number of hours lasting for each task decreases since tasks are being worked on and finished. If the task is not started yet, the size of the task may remain the same every day until the task is begun. Sometimes its size may remain the same even after the team has started working on it or increases day over day, either since no work eventuated on the task the earlier day, or work took place the earlier day but the assessed effort remaining is the same.

What does a sprint burndown chart depict?

• Total estimate of the efforts in hours in a sprint
  It is the calculation of total work in hours for User Stories and other work items which the team is committed to.
• Total amount of effort remaining in a sprint
  This is what sprint burndown chart depicts and this is why this graph got its name which simply means “effort burndown chart”. Every day the team will burn down some effort, so definitely no work effort remains on last day of the sprint.
• Total number of working days in a sprint
  The graph shows this because it is essential for a team to estimate and thoroughly work on the committed work every day. In fact, this is nothing but your sprint duration
• Ideal Effort
  It is drawn by evaluating the accurate amount of effort remaining which needs to be burnt down by the team in a sprint. This serves as a reference for a team and this is why we see it as a very straight line from the top of Y-axis to X-axis.
• Real Effort
  Real effort line shows the effort remaining. This line varies from day to day and team to team as it completely relies on the effort remaining every day. For instance, if more items are added once the sprint started, this appears as an upward spike. Similarly, the line comes down on finishing the tasks every day.

How to read a sprint burndown chart?

The team evaluates the work for all the tasks it engaged in at the start of an iteration itself. Anytime we could assess a trend line depending on the historical data and utilize that trend line to check when we are probably going to complete if the current scope and pace stay consistent.

Fig: Sprint Burndown chart with trend lines

The three burndown lines that are overlapped as shown in the figure above demonstrate distinct situations.

• If the trend line intersects the horizontal axis close to the end of the sprint duration, we can conclude that we have completed all the tasks “on time”.
• If it lands to the left, we can infer that we have finished the tasks “Early” and should probably check whether we can securely adopt extra work.
• If it lands to the right, it means we are “Late” in finishing, either because we have taken a lot of work or we are not continuing at the expected pace or both. At this point, we should explore more to perceive what’s behind the data and what went wrong.

By estimating the trend lines, we will get the data that shows us how we are managing flow within the sprint. This chart also helps in assessing the following:

• How good is the team with the planning?
• How effectively is this team performing against the stories planned in a sprint?
• Is the team self-organized and working in unity?
• What refinements can this team do?

Benefits of using sprint burndown charts

• Perfect Planning and tracking
  The team updates the ‘estimated effort’ and ‘effort remaining’, and also performs task breakdown using this burndown tool, which is the great advantage of using it.
• Risk reduction
  This chart provides feedback on schedule and effort on a daily basis, thus reducing risks and alerts the team instantly if anything goes wrong, instead of waiting until the end.
• Effective communication
  Sprint burndown chart provides visibility of the progress of a project each day. It can be represented physically using a chart paper/whiteboard for better communication if in case we are not able to access the online tool.

Common mistakes people make in the use of sprint burndown charts

• Plotting the ‘effort spent’ and ‘effort remaining’ wrongly, which results in an inaccurate report and so people get confused.
• Forgetting to update the time remaining for tasks which leads to invalid data.
• Choosing too big tasks than what can be done and hence facing the difficulties in tracking the project’s progress.

What is the outcome of a sprint burndown chart?

On the whole, sprint burndown chart motivates team members at the individual level, offers a good vision for decision-making and task tracking activities, and enables the team to identify obstacles early.

The team members can adapt to changes easily with the help of this sprint burndown chart almost every sprint.