SOA is a set of design principles for building a suite of interoperable, flexible and reusable services. These design principles include discoverable service contract, loose coupling, service abstraction, service reusability, service autonomy, service statelessness and service compos ability.
A successful SOA implementation can reduce IT costs by increasing reusability. SOA’s flexible mesh of services can also reduce time to market. SOA also helps to leverage existing investments by wrapping legacy applications in a mesh of reusable services.