Today, enterprises talk about SOAs as the backbone in streamlining their businesses and providing seamless connectivity to customers. A service is a basic unit in the SOA world. SOA is all about segregating services and their associated behaviors, to reuse and leverage a service's capabilities exponentially. SOAs address many of today's enterprise's problems that include security, manageability, interoperability, and so forth.

In short, SOAs serve as a design blueprint that helps enterprises achieve their goals in a more pragmatic way.

SOAs Are Not Web Services

Web services can be one of the realizations of SOA, but not the only one. Web services are becoming more mature and efforts are continuing to be made to use them as an integration tool; these facts drive the adoption of Web services for SOA. SOA strongly emphasizes loose coupling, which is a natural fit for Web services. The reason is so obvious and practical: Web services are becoming the lingua franca of the services paradigm.

SOA Is Not ESB

Forrester Research is quoted as saying the following:

"An enterprise service bus (ESB) is a software infrastructure that enables service-oriented architecture (SOA) by acting as an intermediary layer of middleware through which a set of reusable business services are made widely available. An ESB helps enterprises obtain the value of SOA by increasing connectivity, adding flexibility that speeds change, and providing greater control over use of the important resources it binds.

The wide range of mediation services that can be provided by an ESB fits into a broader architecture pattern, which may be partly or wholly implemented, depending on the breadth of actual requirements. Any enterprise looking to implement SOA should evaluate what form of ESB would be required, and begin to take the initial steps to exploit this key emerging technology."

Nothing in SOA demands an ESB. But, ESB could potentially enable an SOA with its current support for standards and its wide acceptance among SOA solution implementers. In a nutshell, SOA is more than ESB or Web services.

Pain Points

Some of the pain points faced by today's enterprises are outlined below.

• Ad hoc integration silos
• Legacy application maintenance and upgrades
• Centralized security challenges
• Proprietary implementations
• Adoption of premature technologies

Over the past decade, enterprises have seen many architectures or paradigms that tried to address some of these issues. None of them, however, succeeded in their efforts to gain mind-share in streamlining the processes that involved simplifying application integration.

Service Orientation: Evolution or Revolution?

Businesses have to transform rapidly to provide a much healthier atmosphere for customers to sustain in this technology-driven world. Service orientation is an evolution by theory, but revolution by practice. Enterprises must not miss this opportunity to take advantage of SOAs.

This calls for a major rejuvenation of how businesses operate within an enterprise. For example, IT is a major asset to an enterprise. It is also considered to be the backbone of any enterprise. Complexity of IT varies on the size of the enterprise. Managing such complex IT is a challenge to many of the enterprises due to the heterogeneity of applications, platforms, and so on.

The evolution is from Web services to business services to SOA. Services are the least common denominator in the SOA world.

Page 3: SOA Vision