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Subject: RE: [soa-rm] Definition(s) of "service"
Does this imply that if I order a pizza online vs. order a pizza over the phone vs. order a pizza by walking into the store, that these are all separate services?
--JJP
-----Original Message-----
From: Ken Laskey [mailto:klaskey@mitre.org]
Sent: Thursday, August 04, 2005 12:35 PM
To: soa-rm@lists.oasis-open.org
Subject: RE: [soa-rm] Definition(s) of "service"
This gets back to the previous discussion when we talked about
resources, i.e to what extent the service is the mechanism to access
(possibly coordinate) capability vs. when is it considered the
capability itself.
I think any consideration of the service as the capability/resource
should be very limited.
Ken
At 11:07 AM 8/4/2005, Chiusano Joseph wrote:
> > -----Original Message-----
> > From: Ken Laskey [mailto:klaskey@mitre.org]
> > Sent: Thursday, August 04, 2005 11:04 AM
> > To: Chiusano Joseph; soa-rm@lists.oasis-open.org
> > Subject: RE: [soa-rm] Definition(s) of "service"
> >
> > Somehow saying service *provides* capabilities misses the SOA
> > motivation to provide an effective way to bring together the parts I
> > need to solve a problem. Integration is often of disparate parts
> > that exist for their own purposes. Service can help coordinate but
> > the challenge is to make use of the tools/resources/capabilities
> > that already exist, not to create new stovepipes. Saying the
> > service provides all this is a tempting simplification but I fear it
> > will trivialize the concepts most in need of clarification.
>
>Agree - and I should clarify that I was merely saying that a service
>provides capabilities (in general). Combining a capability here, a
>capability there, here a capability, there a capability, everywhere a
>capability (oops sorry - that's the EIEIO song), we have composite
>capabilities.
>
>Joe
>
>Joseph Chiusano
>Booz Allen Hamilton
>O: 703-902-6923
>C: 202-251-0731
>Visit us online@ http://www.boozallen.com
>
> > Ken
> >
> > At 10:35 AM 8/4/2005, Chiusano Joseph wrote:
> > > > -----Original Message-----
> > > > From: Ken Laskey [mailto:klaskey@mitre.org]
> > > > Sent: Thursday, August 04, 2005 10:18 AM
> > > > To: soa-rm@lists.oasis-open.org
> > > > Subject: RE: [soa-rm] Definition(s) of "service"
> > > >
> > > > I'd still like to emphasize service as the access to
> > > > capabilities for which there are extra-service motivations for
> > > > their existence and requirements for use of the capabilities
> > > > that must be
> > navigated
> > > > by the service. Thus,
> > > >
> > > > "A service is a mechanism to enable access to a set of
> > capabilities,
> > >
> > >I would say that access control mechanisms enable such
> > access, and that
> > >the service *provides* the capabilities. Note: Use of
> > "access control"
> > >is too concrete for our RM - I stated it only to illustrate
> > the point.
> > >
> > >Joe
> > >
> > >Joseph Chiusano
> > >Booz Allen Hamilton
> > >O: 703-902-6923
> > >C: 202-251-0731
> > >Visit us online@ http://www.boozallen.com
> > >
> > > > where the access is provided using a prescribed interface and is
> > > > exercised consistent with constraints and policies as
> > specified by
> > > > the service description."
> > > >
> > > > Ken
> > > >
> > > > At 11:15 PM 8/3/2005, joe@pantella.net wrote:
> > > >
> > > > >Just trying to sort through this; some common themes
> > that seem to
> > > > >be
> > > > >acceptable:
> > > > >
> > > > >A service provides capabilities.
> > > > >A service is accessible. (If this is true, then service
> > cannot be a
> > > > >verb.) A service has an interface. (If this is true, then a
> > > > service has
> > > > >a boundary.) A service interface is prescribed. (Then a
> > > > service and its
> > > > >interface are distinct, and the interface has associated rules.
> > > > >I'm not sure this is true, the interface may describe the
> > > > >rules,
> > > > but Im not
> > > > >sure it has rules. In fact, I'm inclined to suggest that
> > > > the interface
> > > > >defines the rules for accessing the service. Which
> > would lead me
> > > > >to suggest that the service interface is more than a
> > > > specification of the
> > > > >data model, but also of the policies associated with the
> > service.)
> > > > >A service is a set of behaviors. (Not sure I'm on board
> > with this,
> > > > >something about behaviors doesn't sit well.)
> > > > >
> > > > >Given this, perhaps something like:
> > > > >
> > > > >"A service is a bounded set of capabilities that are
> > > > accessible through
> > > > >a prescribed interface."
> > > > >
> > > > >
> > > > >-- JJP
> > > > >
> > > > >P.S. I think this definition might just be flexible enough
> > > > to navigate
> > > > >the service offer/contract discussion also.
> > > > >
> > > > >
> > > > >-----Original Message-----
> > > > >From: Schuldt, Ron L [mailto:ron.l.schuldt@lmco.com]
> > > > >Sent: Thursday, July 28, 2005 12:32 PM
> > > > >To: Frank McCabe; SOA-RM
> > > > >Subject: RE: [soa-rm] Definition(s) of "service"
> > > > >
> > > > >
> > > > >Frank,
> > > > >
> > > > >While I believe that the previously proposed definition is
> > > > sufficient,
> > > > >I offer the following as a compromise. Hopefully, the notion of
> > > > >"capabilities" addresses your issue of needing to get
> > things done.
> > > > >
> > > > >"A service is a set of behaviors to provide capabilities
> > > > accessible via
> > > > >a prescribed interface."
> > > > >
> > > > >Ron
> > > > >
> > > > >
> > > > >-----Original Message-----
> > > > >From: Frank McCabe [mailto:frank.mccabe@us.fujitsu.com]
> > > > >Sent: Thursday, July 28, 2005 10:10 AM
> > > > >To: SOA-RM
> > > > >Subject: Re: [soa-rm] Definition(s) of "service"
> > > > >
> > > > >
> > > > >I hesitate to spoil this party ... but I'm going to :)
> > > > >
> > > > >1. There is a distinction between action and result.
> > (Just ask any
> > > > >roboticist) Behaviour sounds a child misbehaving with no
> > > > >discernible effect. Computer Scientists have a tendency
> > to focus on
> > > > >the purely technical aspects of their work: bytes
> > shuffling around
> > > > >at random within hopefully enormous memories.
> > > > >2. Also, we have to bear in mind that nobody invests
> > > > millions of $s (or
> > > > >even 100's of them) in systems that contemplate their navels
> > > > or have no
> > > > >business payoff. I think that we have to directly address the
> > > > >reason that services are deployed. 3. One of the movitating
> > > > >best practice aspects of SOAs is
> > > > that clarity
> > > > >and 'separation' between the providers of services and the
> > > > consumers of
> > > > >services leads to more scalable and robust architectures.
> > > > >
> > > > >All of the above is fuzzy language; but, at the same time,
> > > > "A service
> > > > >is a set of behaviors accessible via a prescribed interface."
> > > > >sounds a lot like bureauspeak.
> > > > >
> > > > >I believe that there is strong consensus on the following
> > > > >characteristics:
> > > > >a. The concept of service is 'at the boundary' between service
> > > > >providers and consumers. b. The service is 'there' to get
> > > > >things done; but doesn't
> > > > itself denote
> > > > >the engine that performs the tasks.
> > > > >c. There is a reason for using a service.
> > > > >d. There is a lot of extra metalogical information about
> > > > services that
> > > > >make it possible for third parties to develop partners
> > for services.
> > > > >
> > > > >I, for one, would prefer a strongly anglo-saxon phrasing of the
> > > > >definition of service that speaks to these points.
> > > > >
> > > > >Frank
> > > > >ti
> > > >
> > > > --
> > > >
> > > > --------------------------------------------------------------
> > > > -------------------
> > > > / Ken
> > > > Laskey
> > > > \
> > > > | MITRE Corporation, M/S H305 phone: 703-983-7934 |
> > > > | 7515 Colshire Drive fax:
> > > > 703-983-1379 |
> > > > \ McLean VA 22102-7508
> > > > /
> > > >
> > > > --------------------------------------------------------------
> > > > --------------------
> > > >
> > > >
> > > >
> > > >
> >
> > --
> >
> > --------------------------------------------------------------
> > -------------------
> > / Ken
> > Laskey
> > \
> > | MITRE Corporation, M/S H305 phone: 703-983-7934 |
> > | 7515 Colshire Drive fax:
> > 703-983-1379 |
> > \ McLean VA 22102-7508
> > /
> >
> > --------------------------------------------------------------
> > --------------------
> >
> >
> >
> >
--
---------------------------------------------------------------------------------
/ Ken
Laskey \
| MITRE Corporation, M/S H305 phone: 703-983-7934 |
| 7515 Colshire Drive fax: 703-983-1379 |
\ McLean VA 22102-7508 /
----------------------------------------------------------------------------------
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