Service Orientation is now established as the leading style of Enterprise Architecture, delivering multiple benefits across the enterprise. SOA started as a technology-led phenomenon. Early implementers found that it can deliver improved information flow and enterprise agility. Others have learned from their example, and the initial trickle of SOA implementation has become a flood.
But SOA can mean many different things. For some, it is just the use of the service principle to define loosely-coupled software modules. For others, it implies an expensive infrastructure including a service registry, and enterprise service bus, a set of development tools, and so on. Are all these necessary? The consensus among SOA experts is that this depends on the needs of the enterprise in question. Different levels of SOA are right for different business organizations. Understanding this is the key to making the SOA investment that will give the best return.
Once you know what kind of SOA you need, there is a growing body of experience and expertise that can help you realise it. This is captured in architectural models and guidance that the professional enterprise architect can use in conjunction with an architecture development method such as that of The Open Group Architectural Framework, TOGAF.