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Proposed Venn Diagrams

From: Champion, Mike <Mike.Champion@SoftwareAG-USA.com>
Date: Fri, 9 May 2003 00:19:52 -0400
Message-ID: <9A4FC925410C024792B85198DF1E97E405A963E2@usmsg03.sagus.com>
To: www-ws-arch@w3.org
I gave myself an action item to produce a Venn diagram to accompany section
1.6 (the text we've been talking about for about 24 hours)  It is attached
in PNG format.

The first captures what I *think* is the consensus from the previous thread
and the call:

SOA is the all-encompassing concept for all this stuff.   I guess
"distributed systems" would be even broaded, and it would include things
like Unix RPC that don't attempt to define any kind of "service" model, but
let's not go there.

The Web IS-A instance of an SOA.  "Uniform Interface Services" aka REST is a
subset of the Web.

Since I don't want to argue about terminology right now, I gave the sets
labels, so "D"  (what people generally think of as "web services") a subset
of SOA and overlaps the Web, but is not a subset of the Web.  "SOAP over
HTTP" is a subset of both the Web and Open Interface Services, but there are
other services that only partially use the Web (e.g. an HTTP gateway into a
mainframe service), and some that don't use the Web at all (e.g COM and

I think the scope of the WSA [warning: this goes beyond anything the WG has
discussed] is roughly set "F". (It might be called "XML Interface Services",
but let's not go there now).  That overlaps the REST circle because one can
(e.g. using SOAP 1.2's GET feature) build RESTful web services; there was
some dispute about that today, but the TAG settled that a year ago and I
ain't a gonna get into that swamp and alligator-wrestle Roy Fielding, no
sir-ee!!  It obviuosly overlaps the "Open Interface Services" circle.  

The second diagram expands the "F" set to indicate that the scope of this WG
maximally includes services that use SOAP (F1), services defined by WSDL
(F2), services that employ both (F12) and services that use XML but neither
SOAP or WSDL (F0).  Perhaps it would be useful to do a poll as to where
people stand on the "in scope" question for these sets:  I personally (not
wearing chair hat or Software AG hat for that matter) think that all of Set
F is in scope.  Andrew Layman seemed to imply that he thinks Set F1 should
be the scope and I believe I've heard the IBM folks imply that Set F2 is the
scope ... and some hard-core people might say that F12 is the scope.  I
believe the Gartner Group defines the F1 U F2 as "web services" (actually
they put UDDI in there too).


Thoughts?  Is this useful? Would the first of these diagrams be useful in
the WD we publish next week? I'm kindof sorry we didn't draw this diagram
and have this argument months ago, but maybe, just maybe we can get a
working consensus at the F2F. 
p.s., In case it's obvious, yes I *am* colorblind :-)  Suggestions for
improving these diagrams are welcome!  I'll attach the PPT in case anyone
wants to fool with them.

Received on Friday, 9 May 2003 00:19:55 UTC

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