Service-Oriented Architecture

SERVICE-ORIENTED ARCHITECTURE

Service-Oriented Architecture (SOA) deals with an architectural approach to the design of a software that is loosely coupled (may be called services) to support the enterprise's processes. In such an environment services are made available, independent of other services and can be accessed without the user knowing about the details of the underlying platform implementation. These services communicate with each other by passing data from one service to another, or by coordinating an activity between two or more services.

It can be said that SOA is an evolution of distributed computing. An application's business logic is modularized and presented as services for consumer applications. The key to the SOA architecture is the term loosely coupled, i.e. the service interface is independent of the implementation. SOA can be seen as a sort of continuum (theory), as opposed to distributed computing or modular programming.

Not all Web services fit into an SOA e.g., fine-grained RPC-type services. Not all SOAs use Web services technology e.g., guaranteed messaging using message-oriented middleware (MOM) technology. Services may be implemented using a variety of techniques such as COM/.NET components, integration server adapters etc.

The shift to a Service-Oriented Architecture ensures the following:

* Function oriented

* Build to last

* Prolonged development cycles

* Coordination oriented

* Build to change

* Incrementally built and deployed

* Application silos

* Tightly coupled

* Object oriented

* Known implementation

* Enterprise solutions

* Loosely coupled

* Message oriented

* Abstraction

SOA is the most promising framework today for changing the way information technology (IT) works, to make IT more agile and responsive to the business, more cost-effective, and more adaptive to the fast-changing business environment.

SERVICE-ORIENTED ARCHITECTURE AND ENTERPRISE INTEGRATION

The loosely coupled nature of SOA allows enterprises to plug in new services or upgrade existing services in a granular fashion to address growing business needs. It also presents the existing legacy applications as services, thereby safeguarding existing IT infrastructure.

Services Oriented Architectures present many challenges today in the integration of existing systems and new systems, and with many times, old legacy mainframe applications. There are many complexities seen in the integration of SOA and mainframe legacy applications.

SOA's greatest value is that it allows enormous interoperability between software, information, and processes. SOA enables a network architect to mix and match existing elements (software, data, or processes) to create custom-made composites to better serve the business's needs.

Enterprise managers can create new services for their clients by taking a component from this application and combining it with a component from another application. In doing so, they can create a new type of service, or a new kind of application, that can serve their clients much, much better.

With SOA, the divisions between proprietary software start to blur. For instance, a network architect can allow users to combine functionality from software by Oracle and Microsoft and Sun all into one composite application. The services offered by these various applications become one composite service.

A service-oriented architecture (SOA) solution streamlines and modernizes IT structures while addressing legacy system and application issues, with minimal or no disturbance to the business. This approach will:

* Synchronize the business processes with technology to make the organization more competitive and responsive to change.

* Measurably improve customer service, satisfaction and loyalty.

* Reduce total cost of IT ownership, freeing funds for strategic business investments.

* Increase operational speed and efficiency, user productivity and organizational flexibility.

* Extend the useful life of in-place investments.

* Consolidate and streamline operations.

* Give timely access to more accurate enterprise information.

* Ease the establishment of secure, real-time communications with partners and customers.

* Help to efficiently manage suppliers, allies and distribution channels.

* Shorten development and time-to-market cycles.

* Create, enable and optimize new long-term revenue opportunities.

SOA is more than an IT solution, it is a paradigm shift. It takes the focus off IT and puts it back where it belongs: on customers, service quality and fundamental business objectives. The overall benefits are a higher return on investment (ROI) and a more agile technology system better able to support execution of strategic decisions.

SOA is fundamentally about describing, building, using and managing the IT environment with a focus upon the services it provides, rather than upon the technology it uses. When enterprises adopt a service-oriented architecture they describe their IT investment in terms of modular services, each delivering specific value. A well architected, governed and managed SOA environment allows enterprises to quickly create, combine and deploy services to respond to rapidly

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