USING BURNDOWN CHARTS
Burndown chart is the most common type of report describing progress of a SCRUM sprint. The web scrumboard application at TangyOrange can automatically prepare current burndown chart as long as work estimates are kept up to date throughout the sprint.
Burndown chart represents changes in the amount of work completed, in progress, and remaining throughout a single SCRUM sprint. Each data series is represented as a separate band: green for work completed, yellow for work in progress, and grey for work not yet started. In a healthy sprint, the amount of work completed increases linearly in time, the amount of work in progress remains approximately constant, and the amount of work remaining decreases linearly.
Burndown chart provides a wealth of information to help manage the sprint as well as improve processes over a number of sprints. Following are examples of some of the common problems burndown chart can help highlight:
- Large amount of work in progress (width of the "in progress" band). A well executing SCRUM team keeps the amount of work in progress (i.e. started but not finished) small throughout the sprint. A wide "in progress" band may indicate that the team is working on too many work items simultaneously. This is oftentimes results from lack of focus in the team, a lot of issues blocking progress, changing priorities, or poor decomposition of user stories into work items during sprint planning. Such sprints frequently finish with a lot of work in progress but little completed.
- Changes in the amount of work remaining (the upper line of the "not started" band). Fluctuations of the total amount of work (completed + in progress + remaining) in time are normal and typically indicate changes in the estimates of remaining work during the sprint. However, sharp increases of the remaining work indicate poor initial estimates of work during sprint planning or discovery of unforeseen work items. For example, the burndown chart above indicates about 7 hour increase of remaining work on 1/10. Such occurrences should be analyzed for any systematic issues which may be addressed better in subsequent sprints.
- Consistency of team execution (does the "completed" band grow linearly). If the amount of completed work remains constant for days in a row only to show a dramatic increase later (usually towards the end of the sprint), the team may have an issue with consistency of execution. If the problem is not addressed, team's execution may not be sustainable over several sprints.
Burndown chart at TangyOrange can be customized to span a specific date range as well show different types of data on the Y axis. By default, the Y axis represents cumulative time estimates from the work estimates entered for individual notes on the scrumboard. Alternatively, the Y axis can show the cumulative number of work items completed, in progress, and not started.
Burndown chart that shows the number of items as opposed to cumulative work estimates can be generated even if the team does not maintain up to date work estimates throughout the sprint. The report is still useful in helping to analyze changes in the number of work items, in particular detecting creation of new work items unforeseen during the sprint planning.
Burndown chart is the key SCRUM report that describes progress of a sprint. While it is often sufficient to enable effective tracking and management of the process, additional insights into the SCRUM data may occasionally be useful. The scrumboard application at TangyOrange supports exporting scrumboard data to a spreadsheet for customized analysis.
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