Meta Data Services Programming
Specializing Relationship Collections
Using derived members makes it possible to create a subset or specialize a relationship collection.
For example, in the following figure, Vehicle is related to Engine through the relationship vehicle has engine. Because the Motor Vehicle uses an Internal Combustion Engine, it requires specializing the general relationship vehicle has engine to motorVehicle has internalCombustionEngine. The last relationship is specialized in Truck to truck has dieselEngine.
For more information about other ways of specializing a collection, see Filtering Derived Collections.