RE: Impact of XML on Data Modeling

> So, what I should have said is that introducing "Person" as 
> the common superclass of "Employer" and "Employee" is 
> something you would normally do in the logical model, but you 
> would only do that in the conceptual model if the business 
> experts view the world that way.

What I usually find is that after a couple of hours with a whiteboard, you
change the way the business people see things. Suddenly they realize that
they have been using a word like "channel" (as in a broadcasting channel - a
real example) or "retailer" to mean three different things, and that this is
why they were getting confused... 

Similarly, when you start asking questions like "How do you handle a
customer who is also a supplier", you may well find one outpost of the
organization that tells you "we lump them together and call them business
partners", and then other people will say that's a good idea, we could do
that too.

So I don't really buy the idea that abstractions can be classified as
business-oriented or technically-oriented. They arise from designing
IT-enabled business processes, which tends to be a joint activity.


Michael Kay
http://www.saxonica.com/