Service Oriented Architecture - SOA Definition

Easy to the point Definition:

The Service Oriented Architecture (SOA) is a design philosophy which defines how a solution should be build.

SOA design approach allow organizations with multiple technologies and platforms to build solutions which are re-useable and accessible across all systems without rewriting of code. All business technologies and functions are treated as services, these services are build to last for long time but service configurations are build for change. This approach creates a loosely-coupled systems which can be changed without spending more money. A loosely coupled system allow business processes to change more quickly as they are not dependent on underlying IT infrastructure.

A service oriented application means writing a highly dynamic, collaborative, stable, dependable application. A application which can act as service to all other business processes/systems without rewriting. The service should not be written for any specific system it should be consumable by any system. The service should use standard protocols (SOAP, XML) to exchange messages between each other. The service should be re-useable, work independently and must be manageable.
Web Services, WSDL, Remote Scripting are common examples of SOA.

SOA - Service Oriented Architecture

Today in the meeting the director declared we will be using SOA design approch for all new development and in next few years all our systems will be using SOA. I guess IBM sales person did a good job, SOA is the future. I dont know our business logics never changes atleast not in last couple of years we are still using multiple technologies from SAP to cobol and one of our core application is still running on IBM AS400 which we have no plans to upgrade (none i know of). The new IT budget close to $90 million is approved so we need to spend money some where i think its a good time for me to ask for a raise in hourly rate too, well i have bills too...

One group of people gets confused that SOA or service Oriented Architecture is some kind of software which we can buy get training on it and boom its all done. The other group takes it as web service or re-useable componenet like COM objects, lot of questions were raised that we are still using it, but i guess hardly any one knew what is service oriented architecture of application is the IBM sales personals tried to define it in easy way that its the future and all enterprise business are using it.

SOA is a design concept for businesses in which all service providers (computer systems) use common standard protocol to talk to each other. The protocol which the sytems use is called SOAP very much like web services a common example i have seen is implemented by Paypal to accepting credits cards on merchant own websites.

I am still researching in more depth on SOA i guess i have used it in many applications with out knowing. I will write on it more later.