Sprint Burndown Chart
The Sprint Burndown chart is often used by Development Teams to track their progress against their Sprint Goal and to determine if they need to course correct or make any decisions about the work with respect to how they are doing.
The mechanics of the Sprint Burndown chart are very simple, as it measures how much work is left on the Sprint Backlog per day. Here we are not really interested in how much work was done, only how much is left to do by the end of the Sprint, and so the focus is on completion and not on how much work in progress we have.
It is usually a good idea to create these charts at the end of Sprint Planning when the team has settled on its Sprint Forecast and how much work is going to be done during the Sprint. Hence, on day 1 of the Sprint we have the total work to be done, and we can draw an ideal “burndown” if everything went well to complete the work in a linear fashion for the rest of the Sprint. Having done this, we can now track day by day how much work we have left to do and compare it to the ideal line.
How It Can Be Used
The Burndown chart originated from Jeff Sutherland, one of the co-inventors of Scrum, and his experience as a fighter pilot for the US Navy [10]. His ideal glide path to land back on the aircraft carrier was known and if he was going too fast with too much throttle, he would have to throttle back. Similarly, if he was going too slow with too little throttle, he would have to throttle forwards to get back on his ideal glide path. Hence, these slight adjustments were made until he could guide the aircraft back to land safely.
In much the same way, if teams find that they are above the ideal glide path, then this may indicate that they have too much work or that the work is more complex than originally thought, and so need to throttle back and discuss with the Product Owner about removing some items from the Sprint in order to get back to their ideal burn down path.
Conversely, if teams find that they are below the ideal burndown then they may opt to increase their throttle and pull in some extra items from the Product Backlog in order to get back to the ideal.
Who It Is For
These decisions are made by the team and help them to focus on what is important for the Sprint and the Sprint Goal with respect to their progress and complexity of the work. Hence, the Spring Burndown chart is really only for the team to use and should not be communicated elsewhere, as they have the context for the information and should be empowered to make their own decisions.
How It Can Be Misused
If Burndown charts are communicated to other parties outside of the team, then this can lead to performance based discussions, which can result in distractions for the team, and the worst possible situation: the team no longer feel safe which can erode their productivity.
Alternatives
Alternatives to the Sprint Burndown chart is the Release Burndown chart which measures how much work is left per Sprint for the release rather than per day as in the Sprint Burndown.