A baseline is a set of projects and tasks used to represent your data at a specific point in time. A baseline has many uses. When you perform an update, Rational Synergy uses a baseline as a starting point to look for new changes. You can also compare two baselines to see what changes have been made relative to a particular build. If you use Rational Change, you can use baselines to generate change request reports.
Typically, a build manager creates a baseline; a developer does not need to create a baseline because he does not make his builds available to other users.
You might find it useful to create a baseline as soon as you perform a build. You can create a baseline and make it available to the test group without making it available to all developers. This is called a test baseline. Making a test baseline as soon as you build saves a representation of the build in Rational Synergy in case it is needed later to create a fix for that particular build.
Creating a baseline for each Integration Testing and System Testing build enables testers and developers to refer back to the set of changes that were used to create the build. Typically, you will create a baseline for all projects in the same release and purpose. For example, you would create a baseline for each Integration Testing build using all Integration Testing projects for that release.
Baselines also improve performance for update operations. An update that uses baselines only needs to analyze the tasks that were added since the last baseline, rather than all tasks for the entire release.