The image shows a diagram of what happens when partial processing is used. The following actions take place:
The client BPEL process has four activities: invoke, receive, invoke, receive.
The call service invoke activity (which appear first) sends a request to the service BPEL process by way of the WSDL partner link.
The service BPEL process has four activities, each of which corresponds to the client BPEL process activities: receive, receive, invoke, receive.
Each of the activities in the service BPEL process passes data back to their appropriate activities in the client BPEL process.