<snip>
The big challenge in ontology is to figure out what’s
different about a system to any other physical item.
[MW] I agree
Why is a car considered a system, but a rock isn’t, for
example. We had a lot of debates around this in IDEAS meetings. You can
easily ascertain the extents of aircraft, armoured vehicles, etc., but the
extent of the classes each nation were calling system differed. The UK
framework (MODAF) saw a system as any kind of man-made object that had
functionality (i.e. cars=yes, rocks and humans = no). The Canadians were very
specific that a physical object only became a system when it was manned,
maintained and ready to function – a narrower set than the UK one. The US
(DoDAF) description was similar to the UK but also included humans/animals. So,
we had three overlapping classes, each of which was called “system”
by different parties. By extensional analysis, we worked out that what MODAF
calls “CapabilityConfiguration” was an exact match for the Canadian
“System”.
[MW] Well I don’t think any of those are wrong, but
perhaps a little restrictive. The two things that characterise a system for me
are:
1.
It has a function/capability/purpose.
2.
Has parts that can be
replaced by functionally equivalent parts.
Regards
Matthew
West
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