There are many approaches to creating an XML payload based virtual service. It really depends on what kind of artifacts you have available. The preferred way of virtualizing XML based payloads are the following:
- Live recording
- You have access to the System/Service to be virtualized
- You have access to the System Under Test (SUT)
- You can reconfigure the endpoint on the SUT to point to recorder instead of live service
- Request Response Pair
- You have access to XML payloads and transport headers
- WSDL
- You have access to WSDL URL or File
Also, values in the headers and body can be configured as variables/properties to make them dynamic. I recommend going over the "Getting Started: CA Service Virtualization" document for more in depth information on the above.