Re: [ontolog-forum] Fw: Thing and Class

["Richard H. McCullough" <rhm@xxxxxxxxxxxxx>]

Sean

 

I have one remaining question -- what does your

concept hierarchy look like? 

 

In my tabula rasa hierarchy, parts are characteristics

of the entity that they are a part of.  So you might

have something like this

 

existent

    entity

        car

    characteristic

        part

            chassis

            engine

    proposition

 

But when the car is disassembled, it would look like this

 

existent

    entity

        chassis

        engine

    characteristic

        part

    proposition

 

Thus my concept hierarchy - my point of view - changes

with time, as the parts are assembled or disassembled.

 

In your case, I would think the designers, manufacturers,

sales personnel, etc. would have different hierarchies.

 

Dick McCullough
Ayn Rand do speak od mKR done;
mKE do enhance od Real Intelligence done;
knowledge := man do identify od existent done;
knowledge haspart proposition list;
http://mKRmKE.org/

----- Original Message -----

From: "Sean Barker" <sean.barker@xxxxxxxxxxxxx>

To: <ontolog-forum@xxxxxxxxxxxxxxxx>

Sent: Saturday, September 06, 2008 3:44 AM

Subject: [ontolog-forum] Fw: Thing and Class

> 
> Dick,
> 
> In engineering practice (at 
least as described through ISO
> 10303), a part is either an inseparable 
component or an assembly. An
> assembly consists of sub-assemblies (which 
are assemblies) and
> components. The definition of assembly is 
recursive.
> 
> A product is a part. In ISO 10303, a part is a 
subtype of a
> product, and this is quite distinct from a product concept. 
Thus, a
> product concept might be "Range Rover", a four-wheel drive 
vehicle,
> which is delivered as physically  as a part RR1-801/1, or 
RR1-801/2, or
> RR1-803/1, or RR1-805/1, or RR2-810/1, etc, where in 
RRx-yyy/z, the RRx
> is the generic part number, the yyy is the 
manufacturing assembly suffix
> and the /z is the version number. In 
theory, all parts with the number
> RR1-801/1 are completely 
interchangeable, and should be interchangeable
> with parts R1-801/2 
(which differs from R1-801/1 in matters not
> affecting form, fit or 
function), however will have some form, fit or
> function difference from 
RR1-803/1.
> 
> The occurrences of the Range Rover concept will also 
be stamped
> with a serial number. A typical maintenance manual will 
inform you of
> changes made in the product standard in terms of the 
serial numbers that
> the change effects - e.g. from 1-100,000 it has a 
2.3 litre engine, and
> from 100,001 onwards the vehicle has a 2.5 litre 
engine. In practice,
> minor changes which internally generate new part 
numbers will not be
> exposed at the level of the maintence 
manual.
> 
> Of course, the real situation is rather more 
complicated, but in
> matters of detail, rather than of substance (in the 
context of this
> discussion).
> 
> The point being, that a 
change approval creates a commitment to
> create a new part (car, wheel, 
bolt, etc) which is either a revision of
> an existing part (form, fit, 
function interchangeable) or a new part. In
> the case of an assembly, 
this may be because it incorporates a new part,
> or a new combination of 
existing parts. Conversely, creating a new
> component part has no effect 
on end product unless it is embodied in the
> chain of assemblies which 
contributes to an actual part (end product),
> which in turn requires that 
a new version of these assemblies is
> produced. 
> 
> The 
issue "is a representation of" versus "is-a" versus
> "is-an-instance-of" 
is a question of how we ground these relationships
> and how we ground the 
concept of part. I ground the concept "part" as a
> "form, fit, and 
function equivalence relation", such that two part
> designs (which 
specify the part) are equivalent if the physical part
> they specify is 
form, fit and function interchangeable. This means that
> the physical 
parts are an instance of the class "part", and that a
> design is a 
specification for the part. That is, the meaning of the
> concept "part" 
is grounded in the results of using individual parts.
> Consequently, a 
design office designs many parts, some of which are
> instantiated by the 
manufacturing department as physical parts. In the
> design office, parts 
instantiate the design process outputs, and are
> treated as separate 
individuals, while in the manufacturing world, a
> part is a class for 
producing physical parts.
> 
> I hope this answers the 
question.
> 
> 
> Sean Barker
> Bristol, UK
> 
> -----Original Message-----
> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
> [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of 
Richard H.
> McCullough
> Sent: 05 September 2008 11:24
> To: 
[ontolog-forum] 
> Subject: Re: [ontolog-forum] Thing and Class
> 
> Sean & Dan
> 
> It is hard for me to understand what 
this discussion is about.
> When I see things 
like
>    part is described by 
design
> and
>    part is instance of 
design
> I wonder if you are missing the whole concept 
of
>    part is part of design
> i.e., the part-whole 
relation.
> 
> In Sean's last email, time dependence is mentioned, 
and I wonder -- are
> you now talking about a part-whole relation which is 
time-varying?
> 
> Dick McCullough
> Ayn Rand do speak od mKR 
done;
> mKE do enhance od Real Intelligence done; knowledge := man do 
identify
> od existent done; knowledge haspart proposition list; http://mKRmKE.org/
> 
> ----- Original Message -----
> From: "Sean Barker" <sean.barker@xxxxxxxxxxxxx>
> To: <ontolog-forum@xxxxxxxxxxxxxxxx>
> Sent: Friday, September 05, 2008 12:25 AM
> 
Subject: [ontolog-forum] Fw: Fw: Thing and Class
> 
> 
>>
>>
>> Dan,
>>
>> While I would 
agree that, say, the CAD model for a part
>> describes the shape of a 
part, the issue is not one of design but of
>> configuration 
management. In particular, the criterion for being a
> part
>> 
A123 is that it is fit, form and function identical to the "typical
>> 
part" A123. The design is an "ontological commitment" that some class
> 
of
>> thing exists (will exist). To reject this is to reject the 
concept of
>> "is-a" and of labelling things with the concepts they 
instantiate.
>>
>> Conversely, penguins do not stop being 
penguins just because some has
>> sequenced their DNA (written down 
their design).
>>
>> The fact that engineering systems are 
concerned with coming-to-be and
>> ceasing-to-be suggests 
that
>> engineering ontologies must use a temporal logic. In fact, many 
>> engineering
>> systems
>> are based on 
effectivities and change notices. The first explicitly
>> identifies 
what components
>> make up a product at a particular time or at a point 
in the product
> run,
>> while th second
>> controls 
when the definitions are changed.
>>
>> Sean 
Barker
>> BAE SYSTEMS - Advanced Technology CentreBristol, 
UK
>>
>> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
>> [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf 
Of Dan
> Corwin
>> Sent: 01 September 2008 19:46
>> To: 
[ontolog-forum]
>> Subject: Re: [ontolog-forum] Fw: Thing and 
Class
>>
>>
>>               
*** WARNING ***
>>
>> This mail has originated outside your 
organization, either from an
>> external partner or the Global 
Internet.
>>     Keep this in mind if you answer 
this message.
>>
>> No magic here, just typical abstract and 
concrete objects.
>>
>> Sean Barker 
wrote:
>>
>>> 2) The product of a design office is designs, 
instances of the
> general
>>
>>> mathom "design". In 
the DO, any class/type structure applied to a set
>>> of designs is 
a generalization of the set of design instances -
>>> designs 
are
>> > not classes for anything.
>>
>> A 
"design" is surely an object in the world of information.
>> It 
describes something, which you portray below as 
concrete.
>>
>>> The product of a manufacturing 
organization is parts, each of
>> > which is an instance of a 
design.
>>
>> Wrong.  Each "part" may be based on the 
"design", but their
>> relation is described/describes, not 
instance/class.
>>
>> regards,
>> Dan 
Corwin
>>
> 
> 
> 
> 
> 
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