Patterns encapsulate a design expert's time and expertise to solve a software problem.
The pattern user does not need to know how to design a pattern, but good pattern documentation is needed for the pattern applier to locate, select, and apply a pattern. The user needs to know what problem the pattern solves, how it is solved and the consequences of applying it. The author of the IBM® Rational® pattern can create multiple types of pattern documentation that are packaged with the pattern. The documentation is readily available for the applier during the pattern application process.
Creating and using patterns promotes software reuse; a pattern is designed once and is used many times. Reuse of patterns potentially lowers production costs and saves time by minimizing the redesign time. Reuse affords higher software reliability and continuity to code design.
You can share patterns within a project, within a company, or across many companies. The limitations of a pattern are determined by the pattern design and the intent of the pattern author. Many patterns are currently documented in software publications and on the Internet.
Rational pattern libraries, containing one or more patterns, are structured as standard Eclipse plug-ins. Maximum pattern reuse is enhanced by packaging pattern plug-ins as Reusable Asset Specifications (RAS) assets and organizing them in RAS asset repositories. Potential pattern users can search for and select patterns from repositories by matching the pattern asset's keywords and descriptions provided by pattern authors. Pattern assets conform to the RAS standards. Adhering to these specifications maintains the requirements for easy exchange of patterns with other Rational pattern users and authors.