Phase Activity in SOA Suite 11g

Couldn't get much details on Phase activity.

The only information is from oracle documentation

http://download.oracle.com/docs/cd/E12839_01/integration.1111/e10224/bp_appx_ref.htm

It says

A.2.13 Phase Activity

This activity creates Oracle Mediator and business rules service components for integration with a BPEL process. You create message request input and message response output variables and design business rules for evaluating variable content for the BPEL process.

When you complete these tasks, the following activities and service components are created:

An assign activity that includes the message request input and message response output variables.

An invoke activity, which is automatically designed to invoke an Oracle Mediator partner link in the BPEL process.

The Oracle Mediator partner link, which is automatically designed to route the message request input variable to the business rules service component in the SOA composite application of which this BPEL process is a part. The business rules service component displays in the SOA Composite Editor. Oracle Mediator also displays as a service component in the SOA Composite Editor.

The business rules service component, which evaluates the content of the message request input variable and returns the results in the message response output variable to Oracle Mediator. Oracle Mediator then makes a routing decision and routes the message to the correct target destinations.

In this exercise we will try to learn more about this activity,how it can be used and what are the best feature of this activity.