A common problem that project managers and product owners encounter during project execution is the question of – how to track your development team’s progress during an iteration or a sprint?
Agile development methodologies offer a solution in the form of an agile burndown chart, a graphical tool to track your progress.
What is an Agile Burndown Chart?
As the name Agile Burndown Chart suggests, it’s a burndown chart used in Agile software development methodologies, e.g., Scrum. So what is a burndown chart?
Burndown charts are graphs that illustrate how quickly your agile development team is executing tasks or user story points. It’s a diminishing slope as you plot the initial number of tasks to do versus time.
The tasks or story points are usually on the y-axis (vertical axis) on the right and time is usually on the bottom on the x-axis (horizontal axis).
Burndown charts track three main things:
- How much work is yet to be done.
- How much time is left to do said work.
- How well you are executing tasks in comparison to your projected execution.
You can also use burndown charts to deduce:
- How much work has been done so far.
- Your development team’s velocity or speed of doing work.
- Estimated/ideal velocity or speed of doing work.
If you are unfamiliar with the term “velocity,” it is simply your development team’s average speed or rate of doing work. It gives a rough estimate of how many tasks your team can complete during a given period or iteration e.g., a sprint.
Not only this, velocity, and by extension burndown charts, can serve as a reliable prediction tool to estimate when your project will be completed. This is because a team’s velocity is usually constant and, therefore, it’s a reliable measure to predict performance and draw estimates.
In essence, burndown charts are simply a visual aid that is easier to understand than plain numbers and words.
Where To Use Burndown Charts? -Types of Burndown Charts
Burndown charts can be used in two main ways:
- As a sprint burndown chart.
- As a product burndown chart.
As a sprint burndown chart: The chart illustrates the amount of work remaining versus the time (usually in days) throughout a sprint. Through a sprint burndown chart, you can analyze and predict your probability of meeting and achieving your sprint goal and targets. A frequently updated burndown chart simplifies sprint management and enables an agile team to quickly correct undesirable trends to stay on target.
As a product burndown chart: In this case, the chart measures larger amounts of work for a longer period. For example, instead of tasks on the sprint backlog, the product burndown chart shows tasks remaining for the entire project. Also, instead of time in days, the product burndown chart considers in terms of sprints.
You can also use burndown charts to illustrate progress on other things besides a sprint or the overall project. For instance, you can use burndowns for releases or epics. Release and epic burndown charts are pretty similar. Their biggest difference is that an epic burndown chart tracks tasks, story points, or features belonging to an epic whereas a release burndown chart tracks tasks, story points, or features assigned to a release.
Burndown charts can also be used outside of software development. For example, imagine you have $1000 that needs to last you until the end of the month. To track and manage your rate of expenditure, you can use a burndown chart to track how fast you are burning through your budget versus the time your budget must last. This way you can quickly see how much money is remaining, how much money you should actually have, and how much rationing needs to be done to go back on target.
Why are Burndown Charts Important?
Burndown charts are useful tools as they provide much-needed insight into your agile team’s performance. Here are some things to look out for:
- If your team regularly completes their tasks after the estimate, it might mean they are handling too much work.
- If your team constantly completes their tasks well ahead of the estimated schedule, they might be too relaxed and are not tackling a sufficient workload or commitments.
- If the graph shows a steep drop during execution, this might mean that you didn’t properly estimate or break down tasks.
A burndown clearly and accurately illustrates the reality of your progress as compared to the ideal rate of progress. However, for this to happen you have to regularly record changes to keep your chart as accurate as possible and up to date.
Above all else, a burndown chart is easy to read and understand. Its ease and simplicity make it a popular progress tracker and effective management tool for many.
Burndown Chart Benefits
Burndowns offer many advantages to organizations and agile teams. Here are some benefits you stand to gain from using them:
- You can track your team’s progress at a glance.
- You can use burndowns to identify and prevent potential bottlenecks.
- They are a good way to maintain momentum as team members work and understand their progress towards their goal.
- Aligns team members towards a common goal as everyone knows what should be done and when it must be done.
- It’s easier to manage and respond to changes as they happen.
- It’s an efficient communication tool that side-steps the need for long conversations about performance.
- Can be used to identify problems in a team’s performance such as over-commitment or under-commitment.
- Can be used to predict when a project will be completed.
Burndown Chart Drawbacks
Although burndown charts have many admirable qualities, they still have their fair share of hurdles you must overcome to use them successfully. For example:
- They require accurate estimation and planning. Without these, any performance measurements will be false and unreliable.
- Following unreliable charts might lead your project and its assessments astray.
- No plan is infallible and therefore it’s inevitable that your backlog will change, work is added, and scope creep occurs. Even though burndown charts are simpler, they fail to show all these changes.
- Burndowns distract agile teams from understanding underlying issues. Instead, teams over-focus on responding to the chart forsaking proper backlog prioritization and due diligence.
- Burndown charts are unreliable when not time-boxed.
- Changing project scopes and status changes (e.g., manpower) are hard to capture on a burndown.
- Does not indicate which tasks have been done.
- Does not show when work has been removed. Instead, removed work/tasks appear as completed tasks.
- Does provide a guide for user story prioritization.
- Burndowns by tasks instead of story points ignore that different tasks require different levels of effort and time.
- Burndowns by stories suffer the same issue as burndowns by tasks. Different stories need different levels of effort and time.
What’s Inside a Burndown Chart?
Now that we know what is a burndown chart and its pros and cons, it’s time we look at the components that make up an agile burndown chart.
Vertical Y-Axis: Work.
Standing upright and to the left is an axis that represents the amount of work. The work in a burndown is usually measured in terms of the number of tasks, user stories, features, story points, or work hours. This is usually common throughout all the different types of burndown charts. During a sprint burndown, the number will gradually decrease to zero as the team tackles their tasks consecutively.
Horizontal X-Axis: Time.
On the floor of your chart lies the axis representing your project/release/epic/sprint timeline. This records the time throughout a burndown. For example, in a product burndown, time is measured in sprints/iterations whereas, in a sprint burndown, time is measured in days.
Ideal Burndown Line.
This line goes by many names. Sometimes it’s also referred to as an “ideal progress line” or “ideal tasks remaining.” This is the line demonstrating the estimated ideal rate of work completion. It’s usually a line with a constant negative gradient or slope – starting from a high value and concluding in a low value (zero). It indicates the ideal number of tasks that should remain at any point along the graph.
Actual Burndown Line.
Similar to the ideal burndown line, the actual burndown line is also sometimes called an “ideal progress line” or “actual tasks remaining line.” This line demonstrates the real or actual rate of work by your development team. It usually fluctuates and therefore, it’s a curve instead of a straight line. At any point along the graph, the actual burndown line shows the exact amount of work remaining.
Agile Burndown Chart Best Practices
A burndown chart serves as a visual communication tool that assists everyone. Therefore, it is recommended to prominently display it on media such as a large screen in a highly visible location. This way everyone is informed about their progress and can deduce how best they should contribute towards it.
A reliable burndown chart needs to be regularly, frequently, and constantly updated. For example, a sprint burndown should ideally be updated at the end of each working day. Doing so ensures that your resulting burndown chart is reliable and accurately represents your rate of doing work.
As previously mentioned, inaccurate estimation for a burndown results in an unreliable burndown chart. Therefore, it’s absolutely vital to accurately size your work. Set a constant unit of measuring the amount of effort each task, feature, etc. needs to complete. For example, you can size your tasks using story points, hours needed, or even invent your own measuring unit.
Use your burndown charts to understand team performance and track progress. Even the best tool is useless if it lies stagnant. Therefore, always use your burndowns to make informed management and execution decisions. For example, if your burndown chart indicates that your team cannot meet their deadline, you can take actions such as adding manpower so that everything goes back on target.
Finally, incorporate the burndown chart during your daily stand-up meetings.
Burndown Chart vs Burnup Chart
The main difference between burndown charts and burnup charts is that burndown charts track the amount of work remaining while burnup charts track the amount of work completed.
Another key difference lies in their appearance, a burndown chart’s lines fall as time passes, whereas a burnup chart’s lines rise as time passes. This means that whereas burndown lines fall to meet zero, burnup lines rise to meet the scope line, which we will explore later.
No plan is infallible and therefore it’s inevitable that your backlog will change, work is added, and scope creep occurs. Even though burndown charts are simpler, they fail to show all these changes. Sometimes during scope creep, your burndown lines may even stay constant giving the illusion that your development team is idling. On the other hand, burnup charts don’t have this problem, when work is added or removed, burnup charts will reflect that change.
The fourth difference between burndown and burnup charts is that whereas burndown charts have two lines (actual and ideal line), burnup charts have three lines which are:
- Ideal burnup line
- Actual burnup line
- Scope line
The scope line is a horizontal, constant line that only trends up or down when the scope is increased or reduced.
In summary, when your scope doesn’t change, burndown charts are more suitable as they are simpler to read than burnup charts. However, burnup charts are more suitable for projects with changing scopes or long projects as they can accurately reflect work done.