This book shows how to apply pattern ideas in business applications. It presents more than 20 structural and behavioral business patterns that use the REA (resources, events, agents) pattern as a common backbone. The book explains the REA patterns in detail, and shows how to find business objects and related modeling elements. The author works at Microsoft Development Center Copenhagen. He shows the developer working on business frameworks how to use the patterns to derive the right abstractions and to design and ensure that the meta-rules are followed by the developers of the actual applications. The application developer can use these patterns to design a business application, to ensure that it does not violate the domain rules, and to adapt the application to changing requirements without the need to change the overall architecture. This approach allows for more flexible and solid software architectures and better software quality.