Reverse of http://unitsml.nist.gov/Schema/unitsmlSchema-0.9.7.xsd.

Note use of UML2 Components as analysis wrappers to construct ana analysis metamodel.

From the perspective of reverse-engineering the NIST UnitsML schema into UML, the heavy use of XSD element references (and the lack of XSD inheritance) is unfortunate; the UML2 wrapper Components afford a mechanism for translating (manually) the XSD references into UML associations. Throughout the diagrams in this trail I have used the following tricks:

• Indirect references from attributes of reverse-engineered XSD complex types to other complex types are mapped using a <<ref>> Dependency (in blue).
• An Association is created from each source wrapper Component to the matching target wrapper Component to construct a wrapping metamodel in UML
• A <<rep>> Dependency (in purple) is created from the Association between wrappers to emphasise that it represents and indirect XSD element reference.

I do not recommend this as a general strategy, I've only used this trick enough here to provide an overview sufficient for the discussions of the SysML working groups.