Business applications are designed using profound knowledge about the business domain, such as domain objects, fundamental domain-related principles, and domain patterns. Nonetheless, the pattern community's ideas for software engineering have not impacted at the application level, they are still mostly used for technical problems. This book takes exactly this step: it shows you how to apply the pattern ideas in business applications and presents more than 20 structural and behavioral business patterns that use the REA (resources, events, agents) pattern as a common backbone. If you are a developer working on business frameworks, you can use the patterns presented to derive the right abstractions (e.g., business objects) and to design and ensure that the meta-rules (e.g., process patterns) are followed by the developers of the actual applications. And if you are an application developer, you can use these patterns to design your 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. As with patterns in general, this approach allows for both more flexible and more solid software architectures and hence better software quality.