-----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