I agree that these
concepts are at the heart of governance. My question is centered on whether
this notion of governance is an inherent part of the definition of SOA.
Rebekah Metz
Associate
Booz Allen Hamilton
Voice: (703) 377-1471
Fax: (703) 902-3457
From: soa-forum-bounces@xxxxxxxxxxxxxx
[mailto:soa-forum-bounces@xxxxxxxxxxxxxx] On
Behalf Of Chiusano Joseph
Sent: Monday, May 08, 2006 10:42
AM
To: Service-Oriented Architecture
CoP; Chris Harding
Cc: soa@xxxxxxxxxxxxx
Subject: RE: [soa-forum] Re:
Definitions of SOA
<Quote>
I
don’t understand why the final two bullets, namely “Requires strong
governance of service representation and implementation” and
“Requires a ‘Litmus Test’, which determined a ‘good
services’ are part of the definition? Who decides
“good” vs. “bad” services?
</Quote>
This speaks to the heart of the
notion of governance, where a governing body (perhaps a Center of Excellence)
would decide "good" vs. "bad" services according to factors
such as adherence to policies, as well as other criteria.
Joe
Joseph Chiusano
Associate
Booz Allen Hamilton
700 13th St. NW, Suite 1100
Washington, DC
20005
O: 202-508-6514
C: 202-251-0731
Visit us online@ http://www.boozallen.com
From:
soa-forum-bounces@xxxxxxxxxxxxxx [mailto:soa-forum-bounces@xxxxxxxxxxxxxx] On Behalf Of Metz Rebekah
Sent: Monday, May 08, 2006 1:28 AM
To: Service-Oriented Architecture
CoP; Chris Harding
Cc: soa@xxxxxxxxxxxxx
Subject: RE: [soa-forum] Re:
Definitions of SOA
A few contextual
comments and questions inline. I typed these originally on Friday night before
the thread of conversation spun out with some other members of the SOA-RM on
this mailing list. However, I think my comments below still apply.
Rebekah
Rebekah Metz
Associate
Booz Allen Hamilton
Voice: (703) 377-1471
Fax: (703) 902-3457
-----Original Message-----
From: soa-forum-bounces@xxxxxxxxxxxxxx
[mailto:soa-forum-bounces@xxxxxxxxxxxxxx] On Behalf Of Andras Szakal
Sent: Friday, May 05, 2006 9:50 AM
To: Chris Harding
Cc: Service-Oriented Architecture CoP; soa@xxxxxxxxxxxxx
Subject: [soa-forum] Re: Definitions of SOA
Team,
I offer this additional chart which depicts the
outcome of our discussion
last week. I am still working the chart but it's a
decent start. We agreed
that SOA is actually only one aspect of this very
interesting industry
initiative that needs our focus.
<RLM>
Although I like the concepts that you’ve related to the notion of
services and SOA, I have a concern that SOA seems to be considered only as a
technology layer concept of a larger concept called SOA. I would challenge
the group to realize instead that SOA is about the alignment of IT with
business. Intuitively, this concept spans the three layers in the first
slide.
As part
of the SOA RM out of OASIS, we initially started down this same path. In
fact, during early drafts of the RM, several members of the TC contemplated
renaming the specification to “Service Reference Model.” In
addition, we spent a significant amount of time working to a description of SOA
that spans these three layers presented - because they are synergistic.
(Note that within the reference model we don’t directly discuss
technologies which are left for Reference Architectures and
Implementations).
I think we need to focus on service orientation as a
superset of the SOA
discussion. In fact one could argue that service
orientation may be
implemented by a combination of architectural styles
and not just SOA/web
services.
I’d
be interested in hearing about what other architectural styles fit the bill.
(See attached file: Service_Orientation_Def_v1.ppt)
<Stepping
onto my soapbox>
The
notion that a service is a “thing” which is separate from a
capability that is served is incorrect. A service is an event. It
is not separate from a capability. It is the performance of that
capability by some entity (service provider) for some other entity (service
consumer). Although it is easy to think about the concept of service in
terms of ‘things’; in actuality, this
concept unifies both active and thing. In the same vein, it is a red
herring to think about SOA as technology only.
In
Slide #2, the discussion of service orientation maps nicely to the treatment of
needs and capabilities as part of the SOA Reference Model. The difference
is that this definition seems to treat service orientation separately from the
core definition of SOA. Instead, brining together needs and capabilities
is of the essence in SOA, an integral part.
The
definition of service speaks of a black box. With this definition, I
would ask what is the role of a service description? Does the existence
of a service interface, and the inputs/outputs with which service interactions
occur part of the black box?
I
don’t understand why the final two bullets, namely “Requires strong
governance of service representation and implementation” and
“Requires a ‘Litmus Test’, which determined a ‘good
services’ are part of the definition? Who decides
“good” vs. “bad” services?
Rebekah
Regards,
Andras
Andras Robert Szakal
Chief Architect IBM Federal Software Group
Distinguished Engineer & Senior Certified IT
Architect
Member Open Group Board of Directors
Tie Line: 930-9215
External Line: 202-595-1678
text message: andras1@xxxxxxxxx
email: aszakal@xxxxxxxxxx
Chris
Harding
<c.harding@opengr
oup.org>
To
Service-Oriented
Architecture CoP
05/05/2006 08:31
<soa-forum@xxxxxxxxxxxxxx>,
AM
"'Service-Oriented Architecture
CoP'" <soa-forum@xxxxxxxxxxxxxx>
cc
soa@xxxxxxxxxxxxx
Subject
Definitions
of SOA
Hi -
As a further update, here is the definition of SOA
that was presented at
The Open Group conference last week (and which we have
shared with the
OMG).
SOA is an architectural style that supports service
orientation
•Service orientation
A way of a way of thinking in terms of services and
service based
development and the outcomes that services bring
•Service
A logical representation of a repeatable business
activity that has a
specified outcome (e.g., check customer credit;
provide weather data,
consolidate drilling reports), is self-contained and
maybe composed of
other Services. It is a black box to consumers of the
Service
•Architectural Style
The combination of distinctive features in which Enterprise
Architecture is
done, or expressed
•The SOA Architectural style’s distinctive
features:
– Based on the design of the services
comprising an enterprise’s
(or inter-enterprise)
business processes. Services mirror real-world
business activity
– Service representation utilizes
business descriptions. Service
representation requires
providing its context (including business
process, goal, rule, policy,
service interface and service component)
and service orchestration to
implement service
– Has unique requirements on
infrastructure. Implementations are
recommended to use open
standards, realize interoperability and
location transparency.
– Implementations are environment
specific, they are constrained or
enabled by context and must be
described within their context.
– Requires strong governance of service
representation and implementation
– Requires a “Litmus Test",
which determined a “good service”
At 20:31 04/05/2006, Cory Casanave wrote:
As an update from the
OMG meeting last week, the SOA SIG adopted the
following definition of
SOA;
Service Oriented
Architecture is an architectural style for a
community of providers
and consumers of services to achieve mutual
value, that:
Allows participants in the communities to work together with
minimal co-dependence or technology dependence
Specifies the contracts to which organizations, people and
technologies must adhere in order to participate in the
community
Provides for business value and business processes to be
realized by the community
Allows for a variety of technology to be used to facilitate
interactions within the community
The corresponding
definition of service has not yet been finalized
but the sense of the
group is that there would be both a
business/domain centric
notion of service as well as an interaction
focused definition.
In both cases this
seems to fit well with the notion of SOA that is
evolving in this group
and in the SOA Demo.
Regards,
Cory Casanave
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