RE: [soa-rm] Definition(s) of "service"

["Chiusano Joseph" <chiusano_joseph@bah.com>]

> -----Original Message-----
> From: Schuldt, Ron L [mailto:ron.l.schuldt@lmco.com] 
> Sent: Wednesday, July 27, 2005 5:34 PM
> To: Duane Nickull; Francis McCabe
> Cc: soa-rm@lists.oasis-open.org
> Subject: RE: [soa-rm] Definition(s) of "service"
> 
> I briefly suggested something similar to this during the F2F
> 
> I'll toss out a slight modification based on this thread to 
> the TC for their reaction.
> 
> "A service is a prescribed interface to a set of behaviors"

I like that much better.

Joe

Joseph Chiusano
Booz Allen Hamilton
O: 703-902-6923
C: 202-251-0731
Visit us online@ http://www.boozallen.com
  
> Ron
> 
> 
> -----Original Message-----
> From: Duane Nickull [mailto:dnickull@adobe.com]
> Sent: Wednesday, July 27, 2005 3:24 PM
> To: Francis McCabe
> Cc: soa-rm@lists.oasis-open.org
> Subject: Re: [soa-rm] Definition(s) of "service"
> 
> 
> Frank:
> 
> I wasn't happy with "observable" either.  Perhaps firing up the ole' 
> thesaurus to find out an "observable / effective / RWE" 
> synonym would be a good idea or just being vague and not 
> using the word. 
> 
> The wording of this is becoming somewhat scatalogical in 
> nature due to the amount of FUD in the industry ;-)
> 
> Duane
> 
> 
> 
> 
> Francis McCabe wrote:
> 
> > I rather like this definition. I agree completely that 
> service should 
> > not mention the delivery mechanism.  Some additional comments:
> >
> > Firstly, I would shorten it to:
> >
> > "A service is an abstract action boundary to a set of behaviours"
> >
> > Rationale: The service is distinct from the results of the service.
> >
> > Secondly, building on the notion that behaviour is different to 
> > effect, I would go on to:
> >
> > "A service is an abstract action boundary to a set of effective 
> > behaviours"
> >
> > Not sure about the word effective, as it may be ambiguous 
> in ordinary 
> > English.
> >
> > Frank
> >
> >
> >
> >
> >
> >
> > On Jul 27, 2005, at 2:04 PM, Duane Nickull wrote:
> >
> >> Perhaps combining all of these is closer to the answer:
> >>
> >> Duane suggests: "A service is an abstract action boundary 
> to a set of 
> >> behaviours or the observable result of some functionality."
> >>
> >> I would want to refrain from mentioning any actors such as 
>  provider, 
> >> consumer, participant in this definition since we may  
> define those 
> >> later by referring to service (avoidance of circular  
> references). I 
> >> used the word "abstract" specific to our RM. In an  RA, it 
> may be a 
> >> more concrete action boundary (see Microsoft def.  below).
> >>
> >> More definitions of services:
> >>
> >> W3C says: "A Web service 
> <http://www.w3.org/TR/ws-arch/#service> is 
> >> an abstract notion that must be implemented by a concrete agent 
> >> <http://www.w3.org/TR/ws-arch/#agent>." (Thank you W3C. I am more 
> >> confused now. Next!)
> >>
> >> Microsoft says: "A software entity whose interactions with other 
> >> entities are via messages. Note that that a service need not be 
> >> connected to a network." (too concrete but good for RA. I 
> wonder why 
> >> they felt compelled to point out that it need not be 
> connected to the 
> >> network to be a service. This is in alignment with our 
> notion of "a 
> >> service is a service, even if not invoked" so I like that part.)
> >>
> >> CISCO says: "A group of related functions (or operations) 
> that work 
> >> together to provide a functional capability." (interesting 
> but does 
> >> really state what a service is, just what it represents).
> >>
> >> The US EPA says: "Breeding, the deposition of boar semen into the 
> >> female." (Hmmm - probably not useful - let's leave this one alone)
> >>
> >> DOI says: "A defined result from a defined action ie, do X and the 
> >> result will be Y. Services perform functions when invoked into 
> >> action." (paraphrased slightly. Too concrete but interesting)
> >>
> >> Apple says: " A service is an I/O Kit entity, based on a 
> subclass  of 
> >> IOService, that has been published with the 
> registerService  method 
> >> and provides certain capabilities to other I/O Kit 
> objects.  In the 
> >> I/O Kit's layered architecture, each layer is a client of  
> the layer 
> >> below it and a provider of services to the layer above  
> it. A service 
> >> type is identified by a matching dictionary that  describes 
> >> properties of the service. A nub or driver can provide  
> services to 
> >> other I/O Kit objects."
> >>
> >> I liked part of the latter analogy about the layering - 
> being a slave 
> >> to the entity above it while being a client of the entity 
> below it. 
> >> This effectively addresses the concept of service  context.
> >> In one context, something is a service consumer while in  
> another it 
> >> is a service provider. The definition is far to specific  to Apple 
> >> but is useful to expand thinking.
> >>
> >> To continue extrapolating from Ken's ramblings, "Two things are 
> >> needed to effectively use a capability under SOA:
> >> - understanding the underlying capability;
> >> - understanding the accessing service."
> >>
> >> I fundamentally think that all that is really required is an 
> >> understanding of the behavioural aspects of the service, the data 
> >> model the service uses, the other metadata and the policies of the 
> >> service.
> >>
> >> Duane
> >>
> >>
> >>>
> >>
> >
>