Re: [soa-rm] Reference Model vs. Reference Architecture (Road Map)

[Matthew MacKenzie <mattm@adobe.com>]

Chiusano Joseph wrote:

> Thanks Matt - this is the one part I am still unclear about:
>  
> <Quote>
> and a trained practitioner knows how to arrange the concepts on her 
> canvas to draw the picture. 
> </Quote>
>  
> Since we are effectively defining here the contents of a pallette, 
> when the painter uses those contents, will the picture that they 
> produce be the equivalent of an architecture for a service-oriented 
> system? It seems that we are saying it would be the equivalent of a 
> reference architecture.

So maybe my analogy could be better.  Without cranking out a diagram, 
here is a useful illustration.

Reference Model -> Reference Architecture -> Architecture
RM is: Abstract -> RA is: Much less abstract -> A is: Concrete
Services, Discovery, Semantics, ... -> SOAP, UDDI, WSDL, ... -> 
POService, http://myuddi, http://myuddi/.../po.wsdl





>  
> If so, what would be the painting equivalent of a reference 
> architecture, knowing that it could not be the actual painting itself? 
> (sorry to not fully understand - grateful for your efforts)
>  
> Thanks,
> Joe
>  
>
> Joseph Chiusano
>
> Booz Allen Hamilton
>
> Visit us online@ http://www.boozallen.com 
> <https://webmail.bah.com/exchweb/bin/redir.asp?URL=http://www.boozallen.com/>
>
> ------------------------------------------------------------------------
> *From:* Matthew MacKenzie [mailto:mattm@adobe.com]
> *Sent:* Wed 5/11/2005 9:30 AM
> *To:* soa-rm@lists.oasis-open.org
> *Subject:* Re: [soa-rm] Reference Model vs. Reference Architecture 
> (Road Map)
>
> In my way of thinking, a reference model is actually a form of
> architecture, although I have been straying away from portraying it in
> that light in order to help others understand the distinction.
>
> What form of architecture?  I call it an "architectural framework". 
> (for the sarcastic, you'll note that I am using two of the most overused
> words in our field here, but I feel they work.)
>
> In my world, and architecture must be implementable and should not
> contain too many undefined/undesigned component areas where
> engineers/developers can make grievous mistakes.  On the other hand, an
> architectural framework is somewhat like a UML pallette you would find
> in Visio -- all of the concepts are represented on the pallette, and a
> trained practitioner knows how to arrange the concepts on her canvas to
> draw the picture.  This reference model that we are writing is
> effectively the training material used to train practitioners.
>
> Is that clear, or have I added confusion?
>
> -Matt
>
> Chiusano Joseph wrote:
>
> > <Quote>
> > I would also pick Matt's brain on this subject.  He is far more
> > knowledgeable since he lives in this world every day.
> > </Quote>
> > Thanks Duane - that all makes sense. Matt, I for one would be
> > interested in hearing anything you'd like to add please.
> > 
> > Joe
> > 
> >
> > Joseph Chiusano
> >
> > Booz Allen Hamilton
> >
> > Visit us online@ http://www.boozallen.com
> > 
> <https://webmail.bah.com/exchweb/bin/redir.asp?URL=http://www.boozallen.com/>
> >
> >
> > ------------------------------------------------------------------------
> > *From:* Duane Nickull [mailto:dnickull@adobe.com]
> > *Sent:* Tue 5/10/2005 8:35 PM
> > *Cc:* soa-rm@lists.oasis-open.org
> > *Subject:* Re: [soa-rm] Reference Model vs. Reference Architecture
> > (Road Map)
> >
> > Joseph:
> >
> > I am going to take a try at this. Please forgive this next sentence:
> >
> > "A reference model is a model while a reference architecture is an
> > architecture. "
> >
> > Okay - so what does that really mean (other that I couldn't find
> > appropriate words)?  Not an easy question to answer.
> >
> > There are multiple differences you can state such as "One is
> > implement-able, the other is not".  A reference architecture does tend
> > to be more generic than most use cases would require and would still
> > need to be specialized further for a particular set of requirements.
> >
> > Reference architecture is sort of a proof of concept. Individual
> > requirements and implementations  may vary, but with the
> > data and guidelines from such reference implementations the system
> > designer can make more informed decisions.  A reference architecture
> > also may force you to consider things the RM does not delve into.  The
> > RM for building a house may have a notion of a bathroom and also a
> > kitchen.  The reference model states you have to have one instance of
> > each to fulfill the functional requirements of providing a habitat for a
> > human being, but does not show a level of detail of how you could build
> > a house having both.
> >
> > The reference architecture for a house would delve into how plumbing
> > gets from the source/target to both the bathroom and the kitchen, as
> > well as a documented layout that shows how they are connected and what
> > other common touchpoints and infrastructure they share.  It is a more
> > specific design that can also be further specialized.  It forces someone
> > architecting another house to consider the same question and perhaps
> > even shows them a solution paradigm (example - hide the pipes in the
> > wall).  This also hints at ways of implementing things that are
> > optimized (hiding pipes in the wall is better than running them outside
> > the house in climates where they may freeze).
> >
> > The Reference Architecture for this alleged house can also be modified
> > for someone who owns property that is on a 10 degree slope or is not
> > connected to a city water and sewage system (let's not get into those
> > details).  It may also further optimize the house's orientation to
> > optimize it for natural sunlight and views via windows.
> >
> > The order of abstraction is as follows:
> >
> > 1. Meta models and meta conventions(ADL's and notions such as patterns
> > of pipes and filters, stacks, etc.)
> > 2. Reference Models
> > 3. Reference Architectures
> > 4. Specific Architectures.
> >
> > There is of course, not 100% consensus on this subject and even
> > something as simple as a definition of architecture itself has proven to
> > be very difficult.
> >
> > I would also pick Matt's brain on this subject.  He is far more
> > knowledgeable since he lives in this world every day.
> >
> > Duane
> > Duane
> >
> >
> > Chiusano Joseph wrote:
> >
> > > I think it is very important that at some point we include in our spec
> > > the necessary guidance for users of our spec to move from our
> > > reference model to a reference architecture, and perhaps beyond.
> > >
> > > I have seen so many cases in which the terms "reference model" and
> > > "reference architecture" have been used interchangeably (and sometimes
> > > in the same resource!) that I am no longer crystal clear on the
> > > similarities/differences between the 2. I know that there has been
> > > preliminary discussion that reference model != reference architecture.
> > >
> > > Can someone please provide a clear distinction between the 2, and how
> > > we envision our RM "flowing" into an RA?
> > >
> > > Thanks,
> > > Joe
> > >
> > > Joseph Chiusano
> > > Booz Allen Hamilton
> > > Visit us online@ http://www.boozallen.com <http://www.boozallen.com/>
> > >
> >
> >
> > --
> > ***********
> > Senior Standards Strategist - Adobe Systems, Inc. - http://www.adobe.com
> > Chair - OASIS Service Oriented Architecture Reference Model Technical
> > Committee -
> > http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=soa-rm
> > Vice Chair - UN/CEFACT Bureau Plenary - http://www.unece.org/cefact/
> > Adobe Enterprise Developer Resources  -
> > http://www.adobe.com/enterprise/developer/main.html
> > ***********
> >
>