SOA or Service Oriented Architecture can be defined as an IT Architectural design style and principles that enables the integration of enterprise applications as linked services . The services can be existing legacy applications modules (ERP modules, CRM Modules) that are wrapped and exposed as web services or newly developped service components. Integration of the Service is done using a middleware that provides the capabilities of an Enterprise Service Bus, ESB. The services collaborate by exchanging well formated messages via the middleware.

The SOA design style provides us with the capability to reuse service components accross multiple business processes thereby enabling our information system to response quickly to changes in business requirements while at the same time reducing the cost of IT developments.The SOA design principles includes

• loosely coupling, services fully independent from each other.
• Reusable, single implemention or single instance of a service, services can be reused at runtime and as it is.
• Entensible, coarse grain services can be built from fine grain services (composable)
• Location Transparent, services consumer need not hardcode the location of service providers
• Interoperable, services can be implemented with a variety of technologies, web service, CORBA …
• seperation of concerns, different services accomplish different task
• Modularity is needed, but granularity of services is defined by its reuse potentials and business value.
• encapsulation, hide internal implementation and only exposed well defined interfaces. Interface should exposed methods with business value
• stateless
• Asynchronous

Of these design principles lousely couple, reusable, extensible remain the SOA catalysts for flexible information system and agile business.
For the business, SOA is a enterprise information system design style that exposes an organizations’ business processes as integrated independent service components that collaboration with each other to accomplish business tasks. The order of integration of the service components can be modify at anytime to meet changes in market forces and enabling business agility.

This entry was posted on Monday, June 11th, 2007 at 12:23 pm and is filed under SOA Concepts, ESB, SOA. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.