You must create a message definition file before you can create the message model objects. The message definition file contains the logical and physical model definitions of the objects in XML schema form.
To create a new message definition file that is based on an existing resource:
The new message definition file, with the name that you have specified and a file extension of *.mxsd, opens in the Message Definition editor; you can use the editor to create your own message definitions. If you have chosen to use a target namespace, a directory structure that is based on the URI that you have supplied is created. The new message definition file is placed within this directory structure, which appears in the Broker Development view.