-----Original
Message-----
From: Rob
Bodington [mailto:rob.bodington@eurostep.com]
Sent: 07 March 2005 13:38
To: 'Gyllström Leif';
plcs-dex@lists.oasis-open.org
Subject: RE: [plcs-dex] Classification
of type and individual
Thinking about this
a bit more .....
I think
that this approach will get really complicated.
Imagine
I have a bike design classified as an "ordinary" bike.
I then
build an individual bike from this design.
The
individual bike will be classified as an "ordinary" bike.
I then
make a modification to my individual bike, so it is now a "Souped up
bike".
The
change was not a change to a design, but to my individual bike so "Souped up
bike"
is not
a classification of the design, but a classification of my individual
bike.
So can
we be sure that:
a)
all classifications
of the typical apply equally to the actual thing being
classified.
b)
If we classify a
typical will that classification apply to all of the actual
things
I'm not
convinced (yet)
-----Original
Message-----
From:
Gyllström Leif [mailto:leif.gyllstrom@aerotechtelub.se]
Sent: 07 March 2005 13:11
To:
plcs-dex@lists.oasis-open.org
Subject: SV: [plcs-dex] Classification
of type and individual
I
would suggest that we only classify the typical due to the implications that
the other approach will have on the reference data
library.
We
have agreed that refdata should be regarded as specializations (subclasses)
of PLCS Entities. This would mean that an instance
of
reference data
would have to be defined for both the typical and the actual thing. Yes, OWL
will allow for a class being a subclass of
several Entity
classes. But I'm convinced that this will cause confusion and classes for
typical will only appear as specializations of
the
entity representing the actual etc.
I'm
stongly in favor of keeping the separation of typical and actual,and
exchange both instances, and have a consistent
approach
-----Ursprungligt
meddelande-----
Från: Rob
Bodington [mailto:rob.bodington@eurostep.com]
Skickat: den 18 februari 2005
17:27
Till:
plcs-dex@lists.oasis-open.org
Ämne: [plcs-dex] Classification of
type and individual
Hi
In PLCS we make a distinction
between a typical something and an actual something.
E.g
Part and
product_as_realized
State_definition and
State_observed
We are also able to classify
things.
E.g.
A Part is classified as a
Bicycle
A State_definition is
classified as a Fault state.
The question is, if I classify
the typical things, do I need to classify the actual thing?
For example, if I classify a
Part as being a bicycle, do I need to classify the Product as realised as
representing my bike, as a being a bicycle, or do I just classify the
Part?
Similarly for
states.
If we impose a rule that you
only classify the typical - not the actual, then you will always have to
exchange both the typical and the actual.
Which may be
overkill.
Any thoughts?
Regards
Rob
-------------------------------------------
Rob
Bodington
Eurostep Limited
Web Page: http://www.eurostep.com
http://www.share-a-space.com
Email:
Rob.Bodington@eurostep.com
Phone: +44 (0)1454 270030
Mobile: +44
(0)7796 176 401