RE: Web Service Definition [Was "Some Thoughts ..."]

If only I had a dime, for every "Web Service" definition I came
across, ...  Well, how well off could I be?;-)

So, instead of trying to compile a list which shall soon
become amiss no matter how exhaustive we can make it now with
existing definitions, I'd propose we take a different tack,
to define web services by properties, which are more likely
to remain invariant with time.  

Here's a stab, incorporating much of the WG discussion so far,
plus some external infusion. 

  A web service is a computing entity with the following properties
  (which incidentally sound like requirements also).

  WSP01: A web service MUST be web-addressable, by a URI.

  WSP02: A web service MUST provide standards-based programmatic
  interface with well defined input/output parameters.
  (For the sake of simplicity, RPC returns may be deemed output 
  parameters in web services.)
  
  WSP03: A web service MUST be sufficiently well formulated such
  such it can be unambiguously described using WSDL.  
  
  WSP04: A web service MUST NOT allow the service requester to
  take over its control of execution on its host system.
  
  WSP05: A web service SHOULD be amenable to be a part of the
  aggregation, composition, or orchestration of multiple web
  services, where it assumes the leading or a subordinate role.
  [Is WSP4 as-is adequate in conveying Inter-operability?
  If not, then we need a separate WSPx for Inter-op.]
  
  WSP06: A web service SHOULD make little or no assumption of the
  service requester's hardware platform, programming language,
  and operations before, during, or after the service rendered.
     
  WSP07: A web service MAY make certain assumptions of the policy
  and/or mechanism of the security and/or transport of its host
  system and/or network, mainly for the purpose of optimization.
  (However, it MUST only execute on verified assumptions; and
  SHOULD adapt upon failed assumptions to strive for high
  availability of service.)
  
  WSP08: A web service MAY advertise itself in as many public
  directories as appropriate, such as those operated by the
  UDDI consortium.  

  WSP0x: ?
    
My $.02.

Joe Hui
Exodus, a Cable & Wireless service