The IBM Rational pattern begins with a Unified Modeling Language (UML) model and ends with a Reusable Asset Specification (RAS) pattern in the form of a plug-in. The Java-based pattern implementation model is created automatically by extending two plug-ins: a pattern service and a pattern framework that abstracts the use of the pattern service. Along with a pattern authoring tool and a pattern browsing tool, the pattern service and pattern framework provide the basic functions to structure, design, code, search for, organize, and apply patterns. The pattern authoring tool is the Pattern Authoring view and the browsing tool is the Pattern Explorer view. Rational patterns are used to modify or add elements to a UML model.
The pattern author can focus on the pattern design because the common code and solutions for common tasks are provided. Customizable locations in the pattern code are known as hot-spots and are well documented.
For easy pattern use, the RAS asset structure enables the author to include
different forms of pattern documentation to assist the user to select and
apply the pattern. Depending on the pattern design, the pattern applier has
the flexibility to apply all or only part of a pattern as needed. All patterns
are stored by default in a pattern-type RAS repository and can be organized
into logical tree-based groups. Pattern users can ignore the details of pattern
design and structure but can benefit from applying patterns. The pattern user
can search, organize, and apply patterns with the Pattern Explorer view.