Use extension and subsitutionGroups in XSD

The MDM data model has you extend entities and the implementation of extensions is done via extending the Java classes. For instance if you extend the Person entity then your generated extension class extends "TCRMPersonBObj", however the Java extension and inheritance pattern is not extended to the XSD.

In the XSD your entity would extend CommonExtensionBObjType and can subsitute for CommonExtensionBObjType only, resulting in you having to wrap your extension in a TCRMExtension tag. The also results in *any* entity extension being able to substitute for any other. i.e. an extension to Person can (from an XSD point of view) be used in the TCRMExtension of a TCRMContractBObj in the addContract transaction.

This RFE is for MDM to use the substitutionGroup and extension attributes properly in the XSD. So in the example given my new person extension would extend TCRMPersonBObjType and be able to substitute for TCRMPersonBObj allowing clients to:

- Use extended entities as first class entities like they are in Java
- Emulate an xsd:choice (strictly within the inheritance pattern) which is currently unmodelable
- The above means that entity extensions cannot be used in an inappropriate place

This is not only clearer for customer extensions but would also allow IBM to streamline out of the box implementations of Party search objects - at present searchParty is implemented via an xsd:choice element which customers cannot model in the workbench.