Unified Change Management (UCM) is Rational Software's approach to managing change in software system development, from requirements to release. UCM spans the development life cycle, defining how to manage change to requirements, design models, documentation, components, test cases, and  source code.

One of the key aspects of the UCM model is that it unifies the activities used to plan and track project progress and the work products undergoing change. The UCM model is realized by both process and tools. The Rational products Rational ClearCase and Rational ClearQuest are the foundation technologies for UCM. ClearCase manages all the work products produced by a software project, including both system work products and project management work products. ClearQuest manages the project's tasks, defects, and requests for enhancements (referred to generically as activities) and provides the charting and reporting tools necessary to track project progress.