[1] This principle is directly responsible for the agility promised by SOA as it promotes composing new solutions by reusing existing services.
The same composition concept is inherited by service-orientation, whereby a business process is automated by combining multiple services.
However, within service-orientation there is even greater focus on building services that can be composed and recomposed within multiple solutions to provide the agility promised by the SOA.
As a result of this emphasis, some guidelines are required to develop services that can be effectively aggregated into multiple solutions.
The application of the standardized service contract principle makes the services interoperable with others, and helps to keep the composition design simpler by avoiding the need to perform runtime data model transformation.