Rational ClearCase UCM

Unified Change Management (UCM) is the object-oriented realization of ClearCase, a set of software tools typically supporting the process area software configuration management.

UCM is activity based. The activity object is the basis for sharing information between ClearCase and ClearQuest. In ClearQuest, the activity presents itself as a task on the developers “to do list” query. In ClearCase, the activity connects the task with the actual files that need to be changed in order to accomplish the task (the change set). A new baseline consists of the old baseline plus all checked-in activities to date. By looking at the change sets of those activities, it is possible to know every file that was touched in order to arrive at a new baseline.

UCM is also component-based. Units of code that are developed and built together can be kept isolated until time to integrate with the full codeline. Each UCM component can have its own recommended baseline. A set of component baselines can be used to define the fully integrated main product baseline (composite baseline)

UCM is also project-based. Each codeline can have its own custom set of development policies and can spawn new projects by using its final baseline as a jumping off point for future development.

UCM is a layer built on Rational ClearCase to provide additional software configuration management features. These changes include integration with ClearQuest to enforce defect and change tracking with code development through the use of activities. This is part of the Rational Unified Process that describes the lifecycle of change management for IBM Rational's software development process. It also gives integrators ownership of projects and streams to allow policy and feature management by project leaders and release engineers. UCM removes the ability/requirement that users manage a configuration specification for a view. UCM is used and configured via either CLIs or GUIs.

...
Wikipedia