Burndown chart vs burnup chart
Work remaining falling, or work finished rising, over the same days.
What a burndown chart shows
A burndown chart (often searched as burn down chart) has days on the horizontal axis and remaining work on the vertical axis. An ideal line runs from the total at the start down to zero on the last day. The actual line is what is still unfinished. If the actual line sits above the ideal line, the team is behind the straight-line pace.
Sample, labeled as a sample: a five-day slice of work estimated at 20 points. Ideal remaining: 16, 12, 8, 4, 0. Actual remaining at the end of day 3: 14. The gap is 6 points versus the ideal 8. The chart does not say why. A retro or a fishbone is where why belongs. The chart says the gap exists.
What a burnup chart adds
A burnup chart plots completed work as a line that should rise, plus a scope line for how much was committed. If someone adds 5 points on day 4, the scope line steps up. A burndown hides that moment: remaining work jumps and it looks like the team went backwards. Burnup keeps 'we added work' distinct from 'we finished less'.
Use burndown when scope is frozen and you want a single glance at remaining work. Use burnup when scope moves, which is common. Neither chart replaces a Gantt chart, which shows which task occupies which days.
Steps
- Pick a unit and freeze it. Points, tasks, or hours. Do not mix them on one axis.
- Draw the ideal or the scope before the week starts. A line drawn after the fact cannot guide the week.
- Update at the same time each day. Morning or end of day. Mixed times make the slope meaningless.
- Write one sentence under a gap. The sentence is the cause. The line is only the size of the gap.
Questions
- What is a burn down chart?
- A chart of work remaining over time, with an ideal line from the starting total down to zero. The actual line shows what is still left.
- When is a burnup chart the better picture?
- When work is added or removed during the period. The scope line makes that change visible. A burndown folds the change into the remaining-work line.
- Does the ideal line have to be straight?
- A straight line is the usual reference because it is easy to explain. If you know a day will be a holiday, flatten the ideal line on that day so the comparison stays fair.