CICS validates SOAP messages only to the extent that it is necessary to confirm that they contain well-formed XML, and to transform them. This means that it is possible for a SOAP message to be successfully validated using the WSDL, but then fail in the runtime environment and vice versa.
The WEBSERVICE resource encapsulates the mapping instructions to enable CICS to perform data conversion at run time. A conversion error occurs when the input does not match the expected data, as described in the WEBSERVICE resource.
For example, the WSDL document might specify range restrictions on a field, such as an unsignedInt that can only have a value between 10 and 20. If a SOAP message contains a value of 25, then validating the SOAP message would cause it to be rejected as invalid. The value 25 is accepted as a valid value for an integer and is passed to the application.
A second example is where the WSDL document specifies a string without specifying a maximum length. DFHWS2LS assumes a maximum length of 255 characters by default when generating the Web service binding file. If the SOAP message contains 300 characters, then although the check against the WSDL would validate the message as no maximum length is set, an error would be reported when attempting to transform the message as the value does not fit the 255 character buffer allocated by CICS.