it is important to source IT constructs that directly support the business goals and processes. In order to do so we will explore the six fundamental constructs of service-oriented architecture. Elevation of the notion of the service or service interface and later on the service contract from a programming construct to the level of an architectural abstraction was a key paradigm shift in software engineering. By the service does not stand alone. It needs to be implemented using some component. The data has to be passed to the service to the component back to the databases and data warehouses and information systems in the backend, processing needs to be completed information retrieved and returned to the requester of the service. Thus information is paramount for services. As a service proceeds with its processing there are certain rules that apply. The invocation of the service should be a more intelligent invocation than that of the method on an object. Generally speaking it is common practice to invoke a method on an object without the necessary cards and without the necessary application of rules. It is typically left up to the application logic to implement those rules. With service-oriented architecture is important to although externalize the rules pertaining to a service but make the application of those rules visible to the service consumer or service requester. The service is also governed by a set of policies that allow the service to be changed without having to fundamentally change the implemented capability behind the service. Services should not only respond to a direct invocation but should be able to respond automatically in a subscriber will fashion to the triggering of that even
Thus it is critical to understand the six fundamental constructs of service-oriented architecture: services, processes, components, information, rules and policies and events. Services can be a comic or composite. As they participate as the steps of the business process, services can be invoked at each one of these steps allowing a shared set of common services to be utilized in a BPM context. therefore, processes are also one of the fundamental constructs of SOA.
Your architectural description should capture these six constructs as you meander through the journey of the software development lifecycle.
also, note that all of the six constructs are motivated by business level constructs. The following diagram establishes a relationship tween the business constructs and the corresponding SOA paradigm constructs.