Continuing our architectural discussion of using the web services layer as a pure packaging strategy of a business module, we evolved the architecture further in this article to discuss message interfaces. We've explored both RPC-style and document-style web services and identified issues with WSDL as the interface definition. Using the XSD to define the message interfaces provides separation of responsibility between the business module and the web services infrastructure layers. Further, it allows the enterprise to have its business module interfaces defined and managed by its business groups, where such responsibility belongs. The engineering group is responsible for the implementation of the business functionality and can focus on its task with clear business functionality definitions already provided. Web services and XML technologies are evolving enterprise processes to truly define ownerships and responsibility within groupswithout any constraints of technology, platform, or products used within the enterprise.
Our next article will delve into performance issues and measure web services overhead to determine its usability in production environments.