1

Business processes are end-user applications that perform high-level tasks within your enterprise (for example, fulfilling an order or generating a quote). Business processes provide business functionality by orchestrating operations provided by different business services (depicted in layer 3).

2

Virtual services run in the layer between the business processes and business services. Each virtual service functions as a proxy for a particular business service.

3

Business services are coarse-grain services that perform business-related tasks, such as performing a credit check, setting up a new customer account or checking the status of an order. Business services generally perform their work by invoking the operations of many different technical services (depicted in layer 4).

Because business services represent the point of consumption by end-user applications and processes, they are good candidates for virtualization. Additionally, there are generally far fewer business services than technical services (typically, 10% to 15% of services in an SOA environment are business services).

4

Technical services are fine-grained services that perform low-level tasks and/or utility functions such as updating the employee database, retrieving a customer record or executing a query against the order database. Often, a technical service provides access to the functionality of a specific back-end system such as a CRM system, an order-entry system or a financial system.