(1) An object that represents a stable configuration for one or more components. A baseline identifies activities and one version of every element that is visible in one or more components.
(2) A reviewed and approved release of artifacts that constitutes an agreed basis for further evolution or development and that can be changed only through a formal procedure, such as change management and configuration control. See also release.
(3) A snapshot of the approved project plan and budget, used for comparison purposes as a project progresses.
(4) A snapshot of a configuration item (CI) or a set of configuration items (CIs) frozen at a point in time for a particular purpose. A baseline will often be recorded to ensure that the infrastructure can be restored to a trusted state should a change fail or the CI need to be built again. A baseline will also be established for the roll out of new CIs and for use in a disaster recovery situation.