Re: [soa-rm] Architectural Scope of Reference Model

["Gregory A. Kohring" <kohring@ccrl-nece.de>]

Francis,

You are correct, the last diagram I sent did not reproduce the
semantics of your previous diagram. The one attached to this message
does. It shows contract being realized as metadata as in your original
diagram.

Note: I don't understand your discussion about the "document"
"describing" the contract.  The relationship you depict in your
original diagram is one of "realization" not description and the
latter seems to me more appropriate in this case.

-- Greg


Francis McCabe wrote:
> The problem with this diagram is that it assumes that a contract *isa*
> metadata. I could not disagree more. And UML makes this awkward.
> 
>  The relationship between a contract (which is an abstract entity) and
> its description (which is a document) is one of *describes*.
> 
> On the other hand, a QoS agreement *isa* contract.
> 
> I also included the stuff on choreography, business policy etc.
> 
> I believe that choreography is part of the syntax -- it is part of what
> you need to know about the mechanics of using the service. But it is
> separate from business logic and semantics.
> 
> Frank
> 
> 
> 
> On Apr 20, 2005, at 2:09 AM, Gregory A. Kohring wrote:
> 
>> OK, here is a slightly different view using UML.  In this view
>> metadata is the higher level abstraction, while contract is a more
>> specialized abstraction.
>>
>> -- Greg
>>
>> Duane Nickull wrote:
>>
>>> Francis:
>>>
>>> Cool!  This is perhaps a place where using UML to avoid ambiguity may be
>>> good.
>>>
>>> If I read your diagram, it asserts that "realized as" implies an
>>> "abstract-concrete" association.  I had viewed that the other concepts
>>> are more of a "can be aggregated as part of" association.  My
>>> observation is that usually the abstract-concrete association is often
>>> used for mapping a specific protocol or specification to a concept in a
>>> reference model or reference architecture.
>>> I guess the question we need to consider is "what is the association
>>> between the higher level abstract concept of metadata and specialized
>>> metadata concepts?".
>>>
>>> Anyone care to take a stab at this as a UML class diagram (or answering
>>> the question)?
>>>
>>> Cheers (and beers next week)
>>>
>>> Duane
>>>
>>>
>>>
>>>
>>> Francis McCabe wrote:
>>>
>>>> I prefer the following diagram :)
>>>>
>>>>
>>>> Frank
>>>>
>>>> On Apr 19, 2005, at 9:51 AM, Duane Nickull wrote:
>>>>
>>>>> <Drawing1.png>
>>
>> <metadata.pdf>
> 
> 


-- 
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G.A. Kohring
C&C Research Laboratories, NEC Europe Ltd.
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