The Message Part element contains attributes that associate a Message with XML schema elements and types.
A Message Part can be added to a Message using the right click context menu.
Name - the name of the Message Part.
Type - the XML schema data type.
The WSDL code for a Message containing a Message Part:
<message name="NewOutputMessage">
<part name="OutputMessagePart" element="tns:OutputType" />
</message>