No, there isn't. You adhere to your burn-down, not to your feature set. Scrum is time driven, not task driven. The whole idea is to become better at estimation

No, there isn't. You adhere to your burn-down, not to your feature set. Scrum is time driven, not task driven. The whole idea is to become better at estimation so that Scrum appears task driven, when really it's just because your team is that good at estimating. Erm. There is an explicit commitment by the Scrum team to complete the stories selected to produce the next increment in the sprint. To quote from http://www.scrum.org/Portals/0/Documents/Scrum%20Guides/Scrum_Guide.pdf http://www.scrum.org/Portals/0/Documents/Scrum%20Guides/Scru... "The two parts of the Sprint Planning Meeting answer the following questions, respectively:  What will be delivered in the Increment resulting from the upcoming Sprint?  How will the work needed to deliver the Increment be achieved?" The commitment on delivering a certain chunk of work has been one of the more controversial elements of Scrum. Many people who say they're doing Scrum don't do this. But it is very definitely part of the Scrum process as defined.