Why SOA?

Enterprise architects believe that SOA can help businesses respond more quickly and cost-effectively to changing market conditions[5]

. This style of architecture promotes reuse at the macro(service) level rather than micro(classes) level. It can also simplify interconnection to - and usage of - existing IT (legacy) assets.

SOA Practitioners Guide: Why Services-Oriented Architecture? provides a high-level summary on SOA.

In some respects, SOA can be considered an architectural evolution rather than a revolution and captures many of the best practices of previous software architectures. In communications systems, for example, there has been little development of solutions that use truly static bindings to talk to other equipment in the network. By formally embracing a SOA approach, such systems are better positioned to stress the importance of well-defined, highly inter-operable interfaces.[citation needed]

Some have questioned whether SOA is just a revival of modular programming (1970s), event-oriented design (1980s) or interface/component-based design (1990s)[citation needed]. SOA promotes the goal of separating users (consumers) from the service implementations. Services can therefore be run on various distributed platforms and be accessed across networks. This can also maximize reuse of services.