>However, as far I can see (I have not looked very hard), this
vocabulary is for "per-item" information, not "summary" information such
as "number of aircraft" (at an airport).
I think this is a classic example of how the data model doesn't lead
directly to the message design. The data model will tell you that
there's a relationship (or multiple relationships) between planes and
airports; only the process model can tell you that in a particular
message, what you need to include is data derived from this
relationship, namely the number of aircraft due to land at the airport
in the next hour.
Michael Kay
Saxonica
