Service Oriented Architecture (SOA) plays a key role in Applications Integration, if there is many applications in the enterprise sometimes there will be needs that one or two applications to communicate with each others for example the HR system needs to communicate with the Financial System in that case there will be some changes on the Source Code for both this mean there will be high cost, but in SOA Standardized services you will enable disparate applications to quickly and easily connect. This will reduce cost of integration and that what management wants....
On the following Link you will find helpful Information about SOA:
http://www.oracle.com/technologies/soa/index.html
Thanks....
