When you generate for BPEL4WS, two types of files are generated:
A file with a .BPEL extension that corresponds to the process file. It contains process descriptions (activities). It is generated for each top-level process you select in the Selection page of the Generation dialog box
A file with a .WSDL extension that corresponds to the process language definition file . It contains properties, property aliases and service link types. It is generated once for the entire model
The generation of the WSDL file depends on the options you have selected in the Options page of the generation dialog box.
For more information on the generation options see Selecting BPEL4WS generation options.