 designers seem to be moving towards, see OCL in the 
UML for example).

&gt;Of course ISO15926-2 is a data model developed specifically to solve this
&gt;sort of problem, with ISO18876 an architecture and methodology for it.
&gt;
&gt; &gt; We then &quot;compiled&quot; the ontology by hand into
&gt; &gt; a relational
&gt; &gt; database.
&gt;
&gt;MW: Most data modelling tools can compile automatically to a relational
&gt;database, so more expense here.

True, but that's only because these modeling tools are 