It is very confusing that creating a "Source Function" and creating a "Procedure" both end up with model objects of type "Procedure." The source function wizard sets a procedure's "function" property to "true" and requires the user to create one or more inputs and one output. However, after finishing the wizard, the user is free to delete the inputs, delete the output, and set the "function" property to "false" if they so choose (in essence making it just a procedure). Alternatively, the user could start by creating a procedure, then set the "function" property to "true," add one or more inputs, add an output, and end up creating a "source function." Maybe the source function wizard could be adapted and used when creating procedures.