What is a Burnup Chart?
A burnup chart plots completed work rising toward a total-scope line over time. Unlike the burndown, it shows scope changes explicitly: when the target line jumps, everyone sees the goalposts move — which is exactly the honesty burndowns can hide.
Choose it whenever scope churns: it separates "team slowed down" from "work grew," two problems that need opposite conversations.
Worked example
A release burnup shows the done line climbing steadily — and the scope line climbing almost as fast, thanks to change requests. The team isn't slow; the target is running away. That one picture converts a "why are you behind?" meeting into a "what should we stop adding?" meeting, which is the meeting the project actually needed.