Since the start of the slow recovery from the dot.com crash of 2001, the assumption has been that new investments in IT would only be forthcoming if the resulting systems could demonstrate real additional value to the business. Underlying this is the need for better alignment of IT with business requirements, and a changing business and political landscape that inevitably means that systems must become more adaptable and interoperable. Service Oriented Architecture (SOA) represents the architectural approach to making this adaptability a sustainable reality.
SOA gained immediate acceptance in a small number of large enterprises, particularly in the financial services, government, and (in Europe) telecommunications sectors. Common factors in all of these are the complex infrastructure (often with deeply embedded legacy systems that would be a nightmare to replace), and the need to deliver rapidly new strategic, innovative services to an increasingly-demanding consumer base. The value of successful deployments (and the cost of being late to market) gave a huge impetus to SOA, and has resulted in many IT vendors committing vast sums to the development of SOA infrastructure and management technology, and for application vendors to commence multi-year projects to re-architect their application suites to be more SOA-friendly.
