Re: [soa-rm] Definition: Services

[George Percivall <percivall@opengeospatial.org>]

We use this set of coordinated definitions:

-  Service:  distinct part of the functionality that is provided by an
entity through interfaces.
-  Interface: named set of operations that characterize the behaviour of an
entity.  
-  Operation: specification of a transformation or query that an object may
be called to execute. It has a name and a list of parameters.

These definitions were developed using UML, RM-ODP, OSE and early versions
of WSDL.

Officially I am an observer on SOA, representing the Open Geospatial
Consortium (OGC).  OGC is a consortium itself with a Service Architecture
that aims to be consistent with the broader IT activities of OASIS.

Regards,
George

George Percivall
Executive Director, Interoperability Architecture
Open Geospatial Consortium
E-mail: percivall@opengeospatial.org
Voice: 1+301-560-6439


On 4/11/05 3:30 PM, "Duane Nickull" <dnickull@adobe.com> wrote:

> I do not like this definition since it assumes that all services are
> used for business processes, which is simply not true.
> 
> I liked Matt's definition from this morning or some variation of it.  We
> had one from the SOA Q&A we did and referenced it form the charter.  Not
> sure if this one still works or if it rubs folks the wrong way.
> 
> Q: What is a service?
> 
> A: A service is a contractually defined behavior provided by a component
> for use by other component(s) based on the contract.
> 
> Google had too many definitions ranging from Church services to
> implementation specific definitions.  Didn't find anything there that
> was abstract.
> 
> I tried to write another one:
> 
> Service: an externally visible behavior of a component offered for
> consumption by other components.  not happy with that.
> 
> The W3C technical note had a pretty interesting definition, albeit once
> more implementation specific to WS*:
> 
> 
>         2.3.2.10 Service
> 
> 
>           2.3.2.10.1 Definition
> 
> A service is an abstract resource that represents a capability of
> performing tasks that represents a coherent functionality from the point
> of view of provider entities
> <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#provider_entity> and
> requester entities
> <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#requester_entity>. To
> be used, a service must be realized by a concrete provider agent
> <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#provider_agent>.
> 
> 
>           2.3.2.10.2 Relationships to other elements
> 
> a service is a <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#isa>
> 
>   resource <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#resource>
> 
> a service performs
> 
>   one or more tasks
>   <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#service_task>
> 
> a service has <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#hasa>
> 
>   a service description
>   <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#service_description>
> 
> a service has a <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#hasa>
> 
>   service interface
>   <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#service_interface>
> 
> a service has <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#hasa>
> 
>   service semantics
>   <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#service_semantics>
> 
> a service has <http://www.w3.org/TR/2004/NOTE-ws-arch-20040211/#hasa>
> 
> 
> 
> 
> 
> 
> Duane
> 
> Services:
> 
> Don Flinn wrote:
> 
>> I just ran across a definition of a service in the paper "Composition
>> Contracts for Service Interaction" Andrade, L. and Fiadeiro, J., which
>> looks good.
>> 
>> Slightly modified -
>> Services are granular software components that can be used as building
>> blocks for the assembly of business processes.
>> 
>> Original -
>> Services can be seen as granular software components that can be used as
>> building blocks for distributed applications or for the assembly of
>> business processes.
>> 
>> Don
>> 
>>  
>> 





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