I disagree with Hitoshi on this (based on OASIS SOA standards). Service Description includes "the semantic capabilities of the service", i.e. business capabilities, plus, other things. Among those, there are the majority of rules (policies) used during the interaction with the service, including communication and execution. These rules are called Execution Context, which comprises Business and Technical contexts.
The only difference of the " instance of an interaction" with this regard is that particular interaction may use a subset of mentioned rules selected and agreed in the Service Contract. - Michael ________________________________ From: Hitoshi Ozawa <[email protected]> To: [email protected] Sent: Sat, December 19, 2009 1:58:13 PM Subject: Re: [service-orientated-architecture] Descriptions vs Contracts Andrew, I think you're beginning to understand the concept, but your example is missing the point. Your analogy with French and English is inappropriate unless you're thinking of a translation service. Service description describes the semantic capabilities of the service while service contract describes the set of rules used in an instance of an interaction. H.Ozawa 2009/12/18 Andrew Herbst <herbst_andrew@ yahoo.com> >Greetings: > >Another question from an SOA neophyte. Thanks for responding to my earlier >questions. > >So, roughly speaking, a service description is like me announcing to the >world: “I can interact in French or in English”, whereas, a service contract >is like me agreeing to speak French with a specific other person in the >context of some very specific interaction. > >I realize this is a very basic question, and it may well not really be the aim >of this group to deal with such basic things. I will therefore take no >offence if no one addresses this. > >Thanks, > >Andrew Herbst > >
