Re: DAML-S/WSEL/WSFL

Thomais Pilioura wrote:

> Hi all,
>
> what is the reletionship of DAML-S to other web services technoligies such
> as WSFL and WSEL?

Here's a brief answer, somewhat over simplified but I think still useful -

First, a brief hi-level veiw of DAML-S.  Three kinds of information will be
needed to characterize a Web service, and DAML-S covers all three areas:

  (1) The "profile", in DAML-S terminology, declares what the Web service does,
for advertising and matchmaking purposes.  That is, it gives the information
needed to evaluate whether the service meets the needs of some requesting
agent.
  (2) The DAML-S "process model" is a lot like a workflow description and tells
how the service works, so that a requesting agent knows precisely what to
expect at each step of service execution, and to allow for monitoring of
service execution and composition of services.
  (3) The DAML-S "grounding" gives details of interacting with a service; that
is, the kind of information that precisely defines the messages that will be
exchanged with the service.  (1) and (2) are thought of as more abstract
descriptions of the service, whereas (3) is at a somewhat lower level, and
spells out the concrete details of mapping (1) and (2) into message formats,
transport mechanisms, etc.

DAML-S is closely related to UDDI, WSDL, and process/flow languages like WSFL
and XLANG.

UDDI provides a registry, and talks about "white pages", "yellow pages", and
"green pages" (technical specs) types of information.  DAML-S can be thought of
as a language for expressing primarily the "green pages" info.  The DAML-S
profile, in particular, is intended for this kind of use.

WSDL defines, among other things, the messages that a service sends and
receives.  This is similar to the idea of the DAML-S grounding.  In fact, the
DAML-S grounding (not yet published, but soon to be) makes use of WSDL.

The DAML-S process model addresses some of the same kinds of issues that WSFL
addresses.  There are many interesting differences, but space, time, and lack
of deep WSFL expertise prevent me from commenting on the differences in this
message.

I hope this is helpful.

Regards,
David Martin


>
>
> By the way does anybody know the state of the IBM's WSEL proposed standard?
> Are there any related documents?
>
> Any feedback or idea would be greatly appreciated.
>
> Thomi Pilioura

Received on Tuesday, 30 April 2002 02:40:46 UTC