The
notion of duality for a service is nice.
Is
it fair to say the thing is the static view and the action the dynamic
one?
Wes
-----Original
Message-----
From:
Bashioum, Christopher D [mailto:cbashioum@mitre.org]
Sent: December 8, 2005 11:11
AM
To: Metz Rebekah;
Chiusano Joseph; Laskey, Ken; soa-rm@lists.oasis-open.org
Subject: [soa-rm] RE: Act versus Object
versus...both?
Wow -
that was a mouthful! ; )
So I
think you said that its ok as long as we all agree that a service is
both a thing and an action - is that correct?
From: Metz Rebekah
[mailto:metz_rebekah@bah.com]
Sent: Thursday, December 08, 2005 10:26
AM
To: Bashioum,
Christopher D; Chiusano Joseph; Laskey, Ken;
soa-rm@lists.oasis-open.org
Subject: Act versus Object
versus...both?
The
phrasing Chris selected prompted something for me…let me see if I can put
words to it. After the discussions yesterday, I spent some time last
night reading linguistic research to try and better understand what about
the relationship between noun and verb forms of ‘service’ are sticking
points for me. As I suspected; it has to with the implications about
the relationships between these lexical forms. What was most
interesting was to realize the variety of aspects to be considered.
However, I think that I found what makes me want to tread careful and
clearly understand and distinguish between service as a noun and service as
a verb.
In
addition, the phrasing you selected suggested that there are two active
portions of the ‘service scenario’:
1)
That
‘of bringing a
desired capability to bear’
2)
That
of the capability itself
I’m
looking right now at the first active portion only. I think we already
recognize the distinction between the two in wd-10. But this served as
a reminder to me.
Essentially, when
using the nominalized form of an active verb like ‘to serve’ in a sentence;
an abstract noun performs most of the work. Nominalization can also
permit the elision of the subject and object of a verb. Therefore, we can
write about a process or action and yet not mention who is involved.
This is part of the sticking point for me when it comes to a reference model
in which we’re trying to unambiguously define key concepts – because we’re
using terminology that permits us to unintentionally cloud the concepts when
we are seeking clarity.
Harrumph. To
me this still wasn’t completely satisfying.
So I
dug a bit further and discovered that there are many ‘types’ of
nominalizations, including ‘episodic nominalizations.’ An
episodic nominalization takes an active process and conceives it as a
noun. So far so good, for service as both noun and verb.
However, here’s where I found some interesting information about the
intuition of language that is captured by these different forms.
Although quite similar, these two forms represent a different semantics
which conceptually develop. In an episodic nominalization, the
conception is no longer viewed as a process but rather as a single episode
(i.e. only as the sum rather than the sum of its parts). Yes this
starts to get into cognitive psychology and linguistics ( and I apologize to
those who just want to know what does the word service mean within the
context of SOA but bear with me).
Where
I got to is that yes, we may actually be talking about the same thing but
from different angles. What I’m recognizing is that those angles come
with specific inferences and assumptions that stem from language itself that
we may not be explicitly aware of and which set up
confusion.
So
what am I saying? That the text in the draft works well to recognize that
the term service(noun) unifies several related concepts – and we do it
justice to recognize those interrelated concepts. Using the
terminology above, they’re conceptualized into a single episode. If we
are clear about that, then I’ll accept that a service can be intended as
either.
(Now
you all know how I spent my evening)
Rebekah
Rebekah
Metz
Associate
Booz Allen
Hamilton
Voice:
(703) 377-1471
Fax: (703)
902-3457
From: Bashioum,
Christopher D [mailto:cbashioum@mitre.org]
Sent: Thursday, December 08, 2005 9:52
AM
To: Chiusano Joseph;
soa-rm@lists.oasis-open.org
Subject: RE: [soa-rm] Proposal:
Reorganization of SOA-RM Draft for Better
Thanks
- that was helpful.
That
being the case, the RM concept of a service maps to a concrete "thing"
called a service, that performs the action of bringing a desired capability
to bear when invoked in the context of an SOA - or at least an RM conformant
SOA.
How's
that for a beltway insider?
From: Chiusano Joseph [mailto:chiusano_joseph@bah.com]
Sent: Thursday, December
08, 2005 9:41 AM
To:
soa-rm@lists.oasis-open.org
Subject: RE: [soa-rm] Proposal:
Reorganization of SOA-RM Draft for Better
Please see
comments below, marked with [JMC].
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: Bashioum,
Christopher D [mailto:cbashioum@mitre.org]
Sent: Thursday, December 08, 2005 9:31
AM
To: Chiusano Joseph;
soa-rm@lists.oasis-open.org
Subject: RE: [soa-rm] Proposal:
Reorganization of SOA-RM Draft for Better
Does that mean that
all the elements in the concept map are only concepts - none of them
translate into objects or actions (or any other concrete
thing)?
[JMC] They
translate into concrete things when an implementation is created that
conforms to the reference model (or an existing implementation is mapped to
it).
I thought one of
the purposes of a RM was to identify and give a language to the basic
elements of the thing being modeled. I.e., and SOA will have all the
elements that are identified in the RM.
[JMC] A SOA
*implementation* may have concrete elements that map to the abstract
elements (concepts) that are identified in the RM.
I think Ken's
description is still the best one, that "a service is a means to bring
a capability to bear in an SOA context". In this case, it is
still a noun (or a thing) (or at least I think so, my wife is the English
major - not me)
[JMC] It is a noun,
as well as an action (alluding to my prior recent post on this). So in
comparison, a political compaign (sorry, I live in Washington DC;) can be thought of as a means to
potentially bring a candidate into elected political office (using very
loose wording here), while "to campaign" is the action that is associated
with that noun. If one had a reference model for campaigns, it would contain
concepts such as "candidate", "policitical party", "regions" (perhaps the
region(s) of the country that their campaign would cover - a gubernatorial
campaign would cover one state, a presidential campaign all states), etc. In
order to campaign (the action), one would leverage the campaign reference
model as a means to guide them in their action of
campaigning.
Joe
From: Chiusano Joseph [mailto:chiusano_joseph@bah.com]
Sent: Thursday, December
08, 2005 6:58 AM
To:
soa-rm@lists.oasis-open.org
Subject: RE: [soa-rm] Proposal:
Reorganization of SOA-RM Draft for Better
I know we're trying to avoid "+1"'s as much as
possible on this list, so I will put it into words: I completely agree with
Duane on all his points just below.
Duane, I'm glad
you've started your guide to concept maps - hopefully in time this will help
the situation. We have used concept maps for the DRM as
well.
Joe
From: Duane Nickull
[mailto:dnickull@adobe.com]
Sent: Thu 12/8/2005 1:40 AM
To: Metz Rebekah; Bashioum, Christopher
D; soa-rm@lists.oasis-open.org
Subject: RE: [soa-rm] Proposal:
Reorganization of SOA-RM Draft for Better
I believe that the
problem, with is largely due to the fact there is no normative reference for
how to interpret concept maps. In this case, a service is neither an
action nor an object. It is imply an abstract
concept.
D
*******************************
Adobe
Systems, Inc. - http://www.adobe.com
Vice Chair -
UN/CEFACT http://www.uncefact.org/
Chair - OASIS SOA Reference Model
Technical Committee
Personal Blog - http://technoracle.blogspot.com/
*******************************
From: Metz Rebekah
[mailto:metz_rebekah@bah.com]
Sent: Wednesday, December 07, 2005 7:18
PM
To: Bashioum,
Christopher D; soa-rm@lists.oasis-open.org
Subject: RE: [soa-rm] Proposal:
Reorganization of SOA-RM Draft for Better
From: Bashioum,
Christopher D [mailto:cbashioum@mitre.org]
Sent: Wednesday, December 07, 2005 5:06
PM
To: Metz Rebekah;
soa-rm@lists.oasis-open.org
Subject: RE: [soa-rm] Proposal:
Reorganization of SOA-RM Draft for Better
Rebekah,
what about the
potential of an act?
[->]
The potential of service is an offer.
I have a problem
with the following
<Snip>
The actual
invocation and performance of the capability is the service; i.e. the
action.
</Snip>
if I understand
what you are saying here, it would imply that a service is not a service
until it is actually performing an action. During the time that it is
"waiting" to perform an action it is not a service, nor is it after it has
completed the action it was created to do.
[->]
yes, you are right. That is exactly what I’m implying. The
service isn’t performing the action, the implementation of the action
is. The service is the performance.
In Duane's diagram,
the service exists independent of the interaction. However, the
interaction is what causes the real-world effect.
I'm not sure I buy
the other statement that a service is an act as opposed to an object.
Isn't it an object (in that it exists) who's purpose is to perform an
act?
[->]
So I’ll ask a question in return. Let’s assume the statement is
true. If a service exists as an object that is independent of the
capability who’s purpose it is to perform; what differentiates the service
from the capability?
For that
matter, is the capability what is actually providing the "action" and the
service is the means to access that action?
[->]
From this perspective, what differentiates the service from the service
access point?
[->]
My point is that the conceptualization of service as an object doesn’t
provide resolution to these questions. It is for this reason that I
started examining service as a verb rather than a noun. From that
perspective, the concepts and the relationships between them
clarified.
Rebekah
From: Metz Rebekah
[mailto:metz_rebekah@bah.com]
Sent: Wednesday, December 07, 2005 4:37
PM
To:
soa-rm@lists.oasis-open.org
Subject: RE: [soa-rm] Proposal:
Reorganization of SOA-RM Draft for Better
Gosh – if this
email came through in some weird format for everyone else, I am terribly
sorry about the wacky formatting of this email thread. Not sure if
everyone saw it as I did, but at least my outlook client puked
=)
Uh-oh. We
seem to be starting to head back to the service as an object as opposed to
an act. I still do not believe that a service is an ‘object.’
In fact, I believe that assumption has caused much of the
difficulty in figuring out what a service actually is.
What is invoked is
a capability, consistent with the execution context and so to produce real
world effects. The actual invocation and performance of the capability
is the service; i.e. the action. Hence I maintain that visibility,
interaction and effect are the interrelated concepts often (yet confusingly)
referred to with a shorthand nomenclature of ‘service.’
As far as roles go,
the very essence of the word service is the recognition that <someone>
does <something> for <someone else>. I would agree that
any other specification of this generalization (uh…isn’t that an ontology)
belongs in something other than the RM.
Rebekah
Rebekah Metz
Associate
Booz Allen Hamilton
Voice: (703)
377-1471
Fax: (703)
902-3457
From: Ken Laskey
[mailto:klaskey@mitre.org]
Sent: Wednesday, December 07, 2005 4:19
PM
To: Metz Rebekah
Cc: Jones, Steve G; marchadr@wellsfargo.com;
tmathews@lmi.org; mattm@adobe.com; soa-rm@lists.oasis-open.org;
frank.mccabe@us.fujitsu.com; goran.zugic@semantion.com;
McGregor.Wesley@tbs-sct.gc.ca; dnickull@adobe.com;
sallystamand@yahoo.com
Subject: Re: [soa-rm] Proposal: Reorganization of
SOA-RM Draft for Better
inline
On Dec 7, 2005, at
4:00 PM, Metz Rebekah wrote:
Comments inline…
From: Ken Laskey
[mailto:klaskey@mitre.org]
Sent: Wednesday,
December 07, 2005 3:43 PM
To: Jones, Steve G
Cc:
marchadr@wellsfargo.com; tmathews@lmi.org; mattm@adobe.com;
soa-rm@lists.oasis-open.org; frank.mccabe@us.fujitsu.com;
goran.zugic@semantion.com; McGregor.Wesley@tbs-sct.gc.ca;
dnickull@adobe.com; sallystamand@yahoo.com
Subject: Re:
[soa-rm] Proposal: Reorganization of SOA-RM Draft for Better
If I invoke a
service, I am a service consumer. It does not matter if I invoke the service
on my own initiative or am told to do it (through a targeted instruction or
as part of a more complex set of instructions), I am still the service
consumer.
[->] Agreed.
I could glibly say
that if I "provide" a service, I'm a service provider, but I fear things are
not that simple. Is the entity that created the service its provider, or the
one who maintains it, or the one who hosts it, or the one who pays for it,
or ...?
[->] I see this
being a question of ‘what are the roles’ versus ‘who plays the
roles’. At first pass, it seems right that we recognize the
roles @ the RM level and leave the details of determining the best way to
decide how to assign some entity into that role to the RA.
I think it is easy
to start naming roles but difficult to stop, and the roles will get more
use-specific.
Luckily, from the
RM standpoint, we don't care.
[->] or do we
just delegate =)
... to someone who
has no choice but to care ;-)
To be used within
the context of SOA, the service must be visible, must be able to take part
in an interaction
[->] Here it
sounds like the service is an active player in an interaction. Isn’t
it that the service consumer and provider interact (as specified…?
Isn't the service
an active player? I invoke it to get its real world effect, so it certainly
sounds like it does something.
(as specified by
the established execution context), and must produce a real world effect
(which I assume may in some circumstances be null). It has been "provided"
but we don't care how or by whom.
So, in summary,
there's a lot of muddy water but sometimes we can avoid playing in it. :-)
[->] Or we can
draw a circle around it and leave that to the RA =)
... at which point
you initially choose RA cases that you can more cleanly defined. You
eventually get to the tougher ones, but we should learn to ride a bicycle
before we get a motorcycle (unless Duane has a different perspective)
If I make a service
available for someone to invoke (and here I would say that "make available"
On Dec 7, 2005, at
4:47 AM, Jones, Steve G wrote:
To add some mud
into the water…