It may occur that a user story starts in a sprint and has to be finished in an other. So what is the best way to manage a user story that spans across several sprints? There are several ways to deal with this in Tuleap Scrum workspace.
Solution 1: create a new story at the end of the sprint
You close the started user story and set the remaining effort to zero. You create a new story with only the remaining work to do and the associated remaining effort. The burndown chart will show your remaining effort at 0 point and resting points will be displayed in the new sprint.
This is the way we use in the Tuleap project development team.
Solution 2: link the story to several sprints
If you prefer, you can choose to link the same story in several Sprints.
The burndown chart will reflect the unfinished first sprint, as there are still remaining work
Note: the remaining effort, mentioned both in the first and the second Sprint, will be take into account only once in the calculation of the Release Burndown chart.
Solution 3: break down a big story before sprints begin
It should be the best practice to avoid this issue, but that's right sometimes development reality prevents us to do so. If you feel that a user story is a big one, you should split it in smaller stories, with a more detailed information level. This way, your team will be able to finish the first part of the story work and continue in the forthcoming milestones. Your burndown will reflect exactly the story progress.
As there is no good or bad solution, choose the option that fit the best with your way of working. If you do in an other way, please share in the comments below, that's interesting