To enable a BPEL process to invoke other services, you need to define the WSDL interface representing the service to be consumed, using an invoke element within the deployment descriptor. For example, in the deploy.xml file:

  <process name="ls:loanApprovalProcess">
      <active>true</active>
      <process-events generate="all"/>
      <provide partnerLink="customer">
        <service name="ls:loanService" port="loanService_Port"/> 
      </provide> 
      <invoke partnerLink="assessor" usePeer2Peer="false"> 
        <service name="ra:riskAssessor" port="riskAssessor_Port"/> 
      </invoke> 
  </process>

Here, the usePeer2Peer property informs the BPEL engine not to use internal communications for sending messages between BPEL processes that may be executing within the same engine, and instead pass messages through the SwitchYard infrastructure.

For each consumed service, you can then create a reference element within the SwitchYard configuration to locate the WSDL file and identify the port type associated with the required WSDL service or port, as shown in the switchyard.xml file below:

  <sca:component name="loanService">
      <bpel:implementation.bpel process="ls:loanApprovalProcess" />
      <sca:service name="loanService">
        <sca:interface.wsdl interface="loanServicePT.wsdl#wsdl.porttype(loanServicePT)"/> 
      </sca:service> 
      <sca:reference name="riskAssessor"> 
        <sca:interface.wsdl interface="riskAssessmentPT.wsdl#wsdl.porttype(riskAssessmentPT)"/> 
      </sca:reference> 
  </sca:component>