A burndown chart is a visual project management tool that tracks the remaining work in a project or sprint over time. It’s one of the most fundamental charts used in Agile software development, particularly in Scrum methodology.
What Does a Burndown Chart Show?
The chart displays two key elements:
- X-axis: Time (usually days in a sprint, or sprints in a release)
- Y-axis: Amount of work remaining (measured in story points, hours, or tasks)
There are typically two lines on the chart:
- Ideal burndown line: A straight diagonal line showing how work should be completed if the team works at a steady pace
- Actual burndown line: The real progress, showing actual work completed each day
Types of Burndown Charts
Sprint Burndown Chart Tracks work remaining within a single sprint (usually 1-4 weeks). Shows daily progress toward completing all committed work by the sprint end date.
Release Burndown Chart Tracks work remaining for an entire release or product milestone across multiple sprints. Helps visualize progress toward major deliverables over weeks or months.
Epic Burndown Chart Focuses on a specific epic or large feature, tracking progress across multiple sprints until that particular functionality is complete.
How to Read a Burndown Chart
Ideal Scenario: The actual line closely follows the ideal line, ending at zero on the final day.
Ahead of Schedule: Actual line drops below the ideal line, indicating the team is completing work faster than expected.
Behind Schedule: Actual line stays above the ideal line, suggesting the team may not complete all committed work on time.
Flat Lines: Horizontal segments indicate periods where no work was completed (weekends, holidays, or blockers).
Scope Changes: Sudden upward jumps in the actual line often indicate new work was added to the sprint.
Practical Uses
Daily Standups Teams review the burndown chart during daily standup meetings to quickly assess progress and identify potential issues. If the actual line is trending upward or staying flat, it triggers discussions about blockers or scope changes.
Sprint Planning Historical burndown charts help teams understand their typical completion patterns and make more accurate commitments in future sprints.
Stakeholder Communication Burndown charts provide a simple visual way to communicate project status to stakeholders who may not be familiar with technical details.
Process Improvement Teams analyze burndown patterns during retrospectives to identify process improvements. Consistently erratic charts might indicate estimation problems, external dependencies, or scope creep issues.
What Burndown Charts Reveal
Team Velocity Patterns Some teams start slow and accelerate toward the end of a sprint, while others front-load their work. Understanding these patterns helps with planning and risk management.
External Dependencies Flat lines often reveal when teams are waiting for external inputs, approvals, or dependencies that block progress.
Scope Creep Upward spikes in the chart indicate new work being added mid-sprint, helping teams recognize and address scope management issues.
Estimation Accuracy Charts that consistently end above or below zero suggest systematic over- or under-estimation that teams can address.
Limitations and Considerations
Work vs. Value Burndown charts track work completion but don’t measure value delivered. A team might complete all tasks but fail to deliver working software.
Gaming the Metric Teams might artificially manipulate the chart by marking tasks complete without proper testing or by breaking large tasks into smaller ones.
Context Missing The chart doesn’t show why work is or isn’t getting done. A flat line could indicate blockers, holidays, or team members working on urgent bug fixes.
Quality Invisible Burndown charts don’t reflect code quality, technical debt, or whether completed work actually meets acceptance criteria.
Best Practices
Update Regularly Teams should update the chart daily, ideally during standup meetings, to maintain accuracy and usefulness.
Focus on Trends, Not Daily Fluctuations Day-to-day variations are normal. Focus on overall trends and patterns rather than minor daily deviations.
Combine with Other Metrics Use burndown charts alongside velocity, quality metrics, and qualitative team feedback for a complete picture of progress.
Address Root Causes When charts show problems, dig deeper to understand underlying causes rather than just pushing for faster completion.
Burndown charts are powerful tools for visualizing progress and facilitating team discussions about work completion, but they work best when combined with other Agile practices and metrics to provide comprehensive insight into team performance and project health.