Well, Kirstan, to answer you question, I might need to write a book :-) but I 
will try to dry it:

1) sure project team cannot and may not wait for "a global SOA initiative" ... 
because it is not its business. SOA is an enterprise 
concept/model/paradigm/architecture, and it has to start over there. This is 
why I always address my notes to the Business/Technical Architects and 
Business/IT decision makers, not to the project team. Those people have to 
obtain the global vision, not necessary an initiative and request vision-driven 
work from the project team

2) maximum what project team can do by itself is a) designing and creating 
solutions as flexible and adaptable as possible; b) reserving hooks and 
placeholders for the extendability in the future, not necessary implementing 
them now; c) creating integral testing environment and challenging new/modified 
pieces against existing services in full w/o stubbing them out. 

3) The most important thing is to understand the nature of the service and 
design respectively, i.e. see a service as an application built on the SO 
principles and driven by business functionality and RWE. For infrastructure 
services, identify technical function which is not implemented already by 
existing drivers like  databases drivers.

4) understand that reuse of services is as dangerous as reuse of API - the 
wider reuse as is , the more difficult and costly to change anything (i.e. such 
reuse may work against adaptability to the required changes). Consider 
mechanisms, which can be easily changed/extended w/o significant problems for 
already existing service consumers (http://soa.sys-con.com/node/523434). 
Finally, return to original meaning of reuse - reuse of existing and legacy 
assets, not services; business services are not reused much in the business

5) accept the idea that SO is function-oriented approach; the function works in 
concrete technical and business environment defined not via function 
implementation but via surrounding policies and regulations. Plus, function 
does not own the data it works on; instead, it owns the meta-data only. The 
data better be organised in canonical models but functions always have their 
own views on the model and it is OK - the only condition here is for functions 
to share the same data 

Oh, I think this is OK for the moment. What do you think?

- Michael




----- Original Message ----
From: Kirstan Vandersluis <[EMAIL PROTECTED]>
To: [email protected]
Sent: Friday, October 17, 2008 9:45:08 PM
Subject: [service-orientated-architecture] Re: van Hoof on EDA & SOA


--- In service-orientated- architecture@ yahoogroups. com, Michael 
Poulin <[EMAIL PROTECTED] .> wrote:
>
> Yes, it was deliberate overstatement though based on OASIS SOA RM 
standard.
> When I talk with people who see value in SOA Projects, I usually 
one of two cases (sometimes, both):
> 1) it is just an initial first pilot project 'to taste the water', 
and it is OK
> 2) Web Services are used for application integration w/o going 
into real SOA value of business functionality
> 
> Actually, I do not mind having SOA projects but only AFTER the 
overall business functionality picture and SOA environment are in 
place: think/see globally and move locally.

Yes, thinking globally and acting locally boils it down nicely.  But 
the reality is there is so much project-level development going on 
that the project group can't wait around for a global SOA intiative, 
if one even exists.  So what advice would you give them?  I would 
say Paul's advice, along with his 4 point clarification, is a good 
start.  In a nutshell, define common messages as the basis of the 
interface for an endpoint, using XML Schema, with an eye towards 
using or building a canonical model (e.g. a "Customer").  Without 
this guidance, you'll end up with JBOWS with little or no reuse and 
agility, and you'll add to the chaos that will have to be fixed 
eventually.

-Kirstan

    

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