A BPEL process uses the definitions from Web Services Description Language (WSDL) files. WSDL files contain the namespace, partner link types, operations, and messages needed to define process activities, and WSDL files are required in order to create a valid, executable BPEL definition.
You can generate WSDL files in Process Developer or you can add them to the Project Explorer view of Process Developer before you begin creating a process definition.
WSDL files provide several key productivity features:
You can drop a WSDL operation onto the Process Editor to automatically create an Web Service interaction activity (Receive, Receive/Reply, Invoke, OnMessage, or OnEvent).
You can automatically create the WSDL extensions required for a BPEL process if they do not already exist (partner link types, properties, property aliases).
You can use the WSDL definitions across processes.
