Progress in XP is measured in user stories that are passing acceptance tests. A user story is deemed completed when and
only when it passes all its acceptance tests. Because customer tests are all automated, this task is actually very
simple since it only consists of running the automated acceptance test suite and comparing the results against the
plan. If 50% (weighted according to cost) of the stories pass acceptance tests, you are 50% done. Hopefully, less than
50% or less of the release has elapsed. If not, it is an indication that the release plan should be revisited.
On a regular basis, the tracker presents the progress the team is making in the release. This information can be
presented in the form of a big, visible chart hanging in the team's open workspace. Progress is often presented as the
number of stories done vs. planned for the release.