Home > Introduction to Service-Orientation > Origins and Influences of Service-Orientation (Part I)
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It is often said that the best way to understand something is to gain knowledge of its history. Service-orientation, by no means, is a design paradigm that just came out of nowhere. It is very much a representation of the evolution of IT and therefore has many roots in past paradigms and technologies. At the same time, it is still in a state of evolution itself and thereby still subject to influences from on-going trends and movements.
Figure: By tracing the primary influences of service-orientation several of its roots can be identified.
The sections that follow describe some of the more prominent origins and thereby help clarify how service-orientation can relate to and even help further some of the goals from past paradigms.
Object-Orientation
In the 1990s the IT community embraced a design philosophy that would lead the way in defining how distributed solutions were to be built. This paradigm was object-orientation, and it came with its own set of principles, the application of which helped ensure consistency across numerous environments. These principles defined a specific type of relationship between units of solution logic classified as objects, which resulted in a predictable set of dynamics that ran through entire solutions.
Service-orientation is frequently compared to object-orientation, and rightly so. The principles and patterns behind object-oriented analysis and design represent one of the most significant sources of inspiration for this paradigm.
In fact, a subset of service-orientation principles (service reusability, service abstraction, and service composability, for example) can be directly traced back to their object-oriented counterparts. What distinguishes service-orientation, though, are the parts of the object-oriented school of thought that were left out and the other principles that were added. See Chapter 14 in SOA: Principles of Service Design for a comparative analysis of concepts and principles associated with these two design approaches.
Web Services
Even though service-orientation as a paradigm and SOA as a technology architecture are each implementation-neutral, their association with Web services has become commonplace - so much so that the primary SOA vendors have shaped their respective platforms around the utilization of Web services technology.
Although service-orientation remains a fully abstract paradigm, it is one that has historically been influenced by the SOA platforms and roadmaps produced by these vendors. As a result, the Web services framework has inspired and promoted several service-orientation principles, including Service Abstraction, Service Loose Coupling, and Service Composability.
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