Re: [soa-rm] FYI: BEA SOA Reference Diagram

[Duane Nickull <dnickull@adobe.com>]

Ken Laskey wrote:

> The essence of a SOA is multiple services coming together to satisfy a 
> set of needs.

This is the core point we have not reached consensus on yet.  This is a 
well worded as can be so I would like to use this assertion as a basis 
for the discussion.

Thoughts:

I would agree that "The essence of a SOA infrastructure is multiple 
services coming together to satisfy a set of needs.  I do have 
reservations about the concept of multiplicity of services being used as 
a key metric to define SOA.

Questions:
1. Is it necessary that there be more than one service in order that SOA 
be SOA? 
2. If yes to #1, is it necessary to call services only in sequence?

My gut feeling is that having multiple services is probably a given for 
any specific implementation of SOA, however it is not a requirements for 
something to be service oriented.  If I architect one application and 
build it with a single service, service description, policy set, (+ 
whateverElseGetsInTheReferenceModel), is that service oriented 
architecture?  I think yes.

I would fully support a reference architecture depicting multiple 
services  being used either sequentially or in parallel, however think 
that is a sub project best left for a dedicated sub committee.

Duane

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