The Service-Oriented Architecture (SOA) has been providing the foundation of business computing. Its ability to significantly accelerate the development of business-critical applications promotes business agility, decreases total cost of ownership, and greatly increases the efficiency and strategic value of IT.
SOA is a business-centric IT architectural approach that supports connecting your business as linked, repeatable business tasks, or services. - IBM
The flexibility of SOA unites both business and IT requirements that can be easily integrated and adapted.
Below are the drivers for the usage of Service-oriented architecture:
Large-scale Enterprise systems
Reduce the cost of doing business
Business process reuse (multiple use cases for the same process)