Michael Champion wrote,
> At some point, we know that the "just write a few lines of code"
> approach breaks down.... or at least that is the conventional
> explanation for why Enterprise Application Integration didn't live up
> to its hype a few years ago.  (N x N little adapters turns into a big
> job as N gets large ...).

Except that it isn't O(n^2), because when n gets large it's very rare 
that everybody needs to be able to talk to everybody else. I have no 
evidence to back this up, but I conjecture that the scaling is much 
more like O(n log n) or better.

OTOH, I believe that the effort involved in getting n parties to agree 
on a common schema or ontology or API scales at O(n^2) or worse. I 
haven't much evidence here either (other anecdotal from experiences on 
too many working groups of one kind or another), but intuitively it's 
due to a mixture of conflicting interests and the fact that the common 
schema/ontology/API would be hard to change if adopted, so has to be 
finessed for flexibility and extensibility far more than would be even 
faintly reasonable for a more local and partial solution.

So, perhaps paradoxically, I believe the exact opposite of the received 
wisdom: mutual agreement on common schemas or ontologies works well in 
the small; but in the large, piecemeal mapping wins.

Cheers,


Miles