Re: [soa-rm] David Linthicum Says: "ESB versus Fabric.Stop It!"

[Rex Brooks <rexb@starbourne.com>]

I tend to think of RM  describing what makes a house different from a 
habitat. As it relates to SOA, the analogy for me lies in describing 
what constitutes being inside the interfaces involved. At this point 
we are still describing only the service. I am assuming still that we 
will move on to include the service consumer as well since I hold 
that an SOA needs both.

Ciao,
Rex

At 11:06 AM -0700 5/24/05, Duane Nickull wrote:
>The RM does not necessarily have to get into cardinality rules IMO, 
>unless they are very obvious.  In the case of a house, you may not 
>make consistent rules stating that every house has to have at least 
>three walls since a wall can be curved or any number of walls from 3 
>up.  You may be able to infer from the relationships that there is a 
>certain cardinality if the RM for a house said that each room has 
>one door.  That would declare an association between the number of 
>rooms to the number of doors.
>
>Structural integrity is an aspect of a wall, which must be 
>specialized for each architecture based on a number criteria.  The 
>RM declares what the wall is and its' purpose, the architect has the 
>job of specifying the actual walls to be used for each architecture 
>and ensuring they map back to requirements.
>
>You are right - analogies are not definitions, however I have found 
>them very useful in conveying the meaning.
>
>Duane
>
>Michael Stiefel wrote:
>
>>Does the RM understand that some of the concepts are unique and 
>>some multiple (without an exact number, you could have one circular 
>>wall, 3 walls, 4 walls, etc.)?
>>
>>Using your analogy, how does the RM deal with concepts such as 
>>structural integrity. Structural integrity would apply to all house 
>>RAs. In my way of thinking concepts such as endpoints or 
>>orchestration are analogous to this.
>>
>>In the analogy I would see the reference architecture as Colonial 
>>American Reference Architecture, or even more specifically Colonial 
>>American Cape Ann, or Colonial American Greek Revival reference 
>>architectures.
>>
>>Analogies are useful, but they are not definitions.
>>
>>Michael
>>
>>At 12:56 PM 5/24/2005, Duane Nickull wrote:
>>
>>>RA means Reference Architecture.  As per the previous emails on 
>>>this subject, it is a generalized architecture.
>>>
>>>The relationship is that architects use a RM as a guiding model 
>>>when building a RA.
>>>
>>>For example, if you are architecting a house, an RM may explain 
>>>the concepts of gravity, a 3D environment, walls, foundations, 
>>>floors, roofs, ceilings etc.  It is abstract however.  There is 
>>>nothing specific like a wall with measurements such as 8 feet 
>>>high.  Note that the RM has only one each of these things - it 
>>>does not have 4, 16, 23 walls, just one as a concept.
>>>The architect may uses this model to create a specific 
>>>architecture for a specific house (accounting for such things as 
>>>property, incline, climate etc) or an architect MAY elect to use 
>>>it to build a more generalized reference architecture.  The latter 
>>>is often done by architects who design houses.  When they sell a 
>>>house, they must often re-architect the RA for specific 
>>>implementation details such as incline of land, climate, facing 
>>>the sun etc..
>>>
>>>So why do we need a RM?  Simple - we now have logical divisions 
>>>amongst the components of a house and what they mean.  That way, 
>>>when a company says " we are a flooring company..", that is 
>>>meaningful since we all know what that means.  The same applies to 
>>>a roofing company.  Without the basic consensus on the logical 
>>>divisions, a roofing contractor may also try to include the 
>>>ceiling and walls as part of his offerings.
>>>That would not work and not allow the general contractor to build 
>>>a house very easily since there may not be consensus upon the 
>>>division of labor and components to build the house.
>>>
>>>Do you guys think an explanation of this nature may be good to 
>>>include in the introduction section?
>>>
>>>Duane
>>>
>>>Chiusano Joseph wrote:
>>>
>>>>What is an RA? What is the relationship between an RM and an RA? What is
>>>>the RM->RA path for SOA?
>>>>
>>>>Matt also submitted last week (I believe) that we may not even need an
>>>>RA. How should that change our notion of RM, if at all?
>>>>
>>>>Joe
>>>>
>>>>Joseph Chiusano
>>>>Booz Allen Hamilton
>>>>Visit us online@ http://www.boozallen.com


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Rex Brooks
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