W3C WS Choreography WG conference call


3rd February 2004



Role Call



 Martin Chapman


Steve Ross-Talbot



W3C Staff Contacts


Yves Lafon


Was this done for the minutes of the 27th January => Members (NOTE THIS IS FROM PREVIOUS WEEK – NEED ROLE CALL RESULTS ADDED)

Anthony Fletcher

Choreology Ltd

David Burdett

Commerce One

Asaf Arkin

Intalio Inc.

Ravi Byakod

Intalio Inc.

Abbie Barbir

Nortel Networks

Greg Ritzinger


Nickolas Kavantzas

Oracle Corporation

Jeff Mischkinsky

Oracle Corporation

Ivana Trickovic


Ugo Corda

SeeBeyond Technology Corporation

Monica Martin

Sun Microsystems, Inc.

Evrin Sirin

University of Maryland


Confirm scribe


Tony Fletcher volunteered to scribe.


The following is a listof recent scribes (in order): Monica Martin, Ugo Corda, Mayilraj Krishnan, Ravi Byako, Martin Chapman, Steve Ross-Talbot, Monica Martin, Nick Kavantzas,Ed Peters, Anthony Fletcher, Jeff Michkinsky,  Dinesh Shahane, Greg Ritzinger, Ed Peters, David Burdett,Ivana Trickovic, Ugo Corda, Assaf Arkin, MonicaMartin, Carol McDonald, Nick Kavantzas, Tony Fletcher, Mayilraj Krishnan, Francis McCabe, Jeff Mischkinsky, David Burdett, John Dart, MonicaMartin,Tony, Fletcher, Jim Hendler, Kevin Liu, TonyFletcher, Jon Dart, DavidBurdett,Ed Peters, Greg Ritzinger, Monica Martin, Len Greski, Jean-Jacques Dubray,Monica Martin, Mayilraj Krishnan, Francis McCabe, Michael Champion,Abbie Barbir, David Burdett, Jon Dart, Carol McDonald,Yaron Goland, Leon Greski,Ed Peters, Greg Ritzinger, Daniel Austin, Peter Furniss, Jim Hendler


Approve minutes

     Minutes 27th January 2004 (Has the attendence been corrected?)
Minutes approved

Action item review



ACTION: chairs should also ask marco to see if his requirements are captured within the latest req-doc (0113, 0120, 0127, 0203) NO PROGRESS.

The Requirements document is still not available for Marco to check.



ACTION: SRT and MM will provide further detail on the “banana-calculus” discussions in order to record this exception/errors discussion properly.  (0127, 0203) NO PROGRESS.

Steve and Monica said they hoped to do by next week.



ACTION:SRT will update bugzilla entries to reflect exceptions/error discussion. (0127, 0203) NO PROGRESS.

depends on previous action which is not done yet.


ACTION: Yves to add editor's draft on the public page (0113, 0120, 0127) DONE.

Yves has been supplied with both HTML and XML versions and the language Model Overview is now available from the public page for this group.


ACTION: Nick to define the features required of an intermediate end-point language (0113, 0120, 0127, 0203) NO PROGRESS.

Nick is waiting for folk to review the Model Overview.


ACTION: convert ER diagrams into UML class diagrams (0113, 0120, 0127, 0203) NOT COMPLETED YET.

David said that the editors intended to discuss on their call this Friday then send out to the group.


ACTION:editors to propose documents and table of contents (0113, 0120, 0127) DONE.

A proposal for the number of documents required and the outline structure for each has been made available on the mailing list and some comments received.

NEW ACTION: editors to revise documents and table of contents according to comments received (0203)


ACTION:Martin/Ritzinger/ALL: Check to confirm proposed F2F  location/dates/availability. (0127) DONE.

Both SUN and Novel could host either 9-11 or 23-25 June 2004.


ACTION: Chairs to look into a far east meeting in sep/oct (0113, 0120, 0127, 0203) IN PROGRESS.

Martin (Chapman) has sent emails soliciting some offers and is awaiting replies.


ACTION: Chairs to organise an issues conference call in which the regular conf call is used with members to look at the issue in bugzilla (possibly the Jan6th conf call) (0113, 0120, 0127, 0203) NO PROGRESS.

Requirements document is still not available for folk to check for issues



ACTION:Yves to steer through W3C procedure for invited experts. (0127) DONE.

Robin Milner and Nobuko Yoshida are new expert members of the group.


ACTION: Chairs  to raise a topic of Binding, Context etc. (0113, 0120, 0127, 0203) IN PROGRESS.

Chairs to add to an agenda soon.


ACTION: Editors to issue requirements document for review on public mailing list for next call (0127, 0203) IN PROGRESS.

Abbie reported that Daniel (who was not on this call) has the XML version and it is now down to him to issue so the action is with Daniel.


ACTION: Chairs to schedule conference call to review requirements document (see above)(0127, 0203) NO PROGRESS.

the Requirements document is still not available.

ACTION: Steve/Martin - let us see some email traffic to manage the process to get the requirements doc reviewed quickly and published -if we cannot make it by 13th (which is tight) then we inform the members as such. (0106, 0113, 0120, 0127, 0203) DEPENDENT ON REQ DOC REVIEW (see above)

ACTION: Task Nick/David to come up with the what to do next by 27th (0106, 0113, 0120, 0127)  DONE.

a proposal for the number of documents required and the outline structure for each has been made available on the mailing list and some comments received.  It is suggested that future plans are based on this list when agreed by the group.


ACTION: Steve to ask WSD WG whether they intend to support publish/subscribe MEP. (0120, 0127, 0203) NO PROGRESS.

Steve forgot to pick this one up and will do so poste-haste.


ACTION: Team to review the Model Overview prior to next meeting. (0127, 0203) IN PROGRESS.

Waiting for the key diagram to be recast into UML form.


Standing tracking items



Requirements Document Feedback

Unfortunately the Requirements document was still not out, but hopefully it will be for review next week.

Issue tracking (progress/review – go through issues list)

They have been no further issues raised pending the new Requirements document

Specification Editors report

           Model Overview

Steve asked about the division into abstract, portable, and concrete levels for the specification - what do I get with each?

David replied that each level allowed the specification of more information.  The abstract level only identifies the semantics of a message.  The portable level is the abstract plus the actual type of document to be used such as UBL, BOD, etc, and includes what security is to be used, what packaging, etc, but does not include the actual communication endpoint.  The concrete level includes the endpoint information and so forth.

Tony asked if therefore the concrete was in fact an instance of the portable version.  David replied no, but there is a separate fourth step, if you like, which is the instance.

Ugo made the point that so far Web Service tradition has it that there are only two levels: abstract and concrete (for instance, WSD and WSBPEL).  He also felt the term ‘abstract’ was being used differently here.  David replied that he thought the levels were appropriate for our situation and that all three would be used.  The abstract level will be used by business people who will want to go beyond Web Services, but not be concerned with the details.

It was noted that the Web Service Description Language (WSDL) has an abstract level, which in principle can go over any protocol.  The binding gives you the concrete level and specifies the actual protocol to be used and so on.  Ugo said he was not sure that the abstract level was within our scope as we are the WS-Choreography group.

David responded that there is a progression from abstract through portable to concrete and that you could not remove the abstract without undermining the whole scheme.  The rationale behind the concrete level is to provide information that is currently in some of the proprietary specifications such as WS-Policy.  One needs to be able to specify sequencing with as little extra as possible, for instance just order, invoice, payment messages then fill in the details later - maybe different people do these different steps - this is a methodology that the language should support, and perhaps should become a new requirement.

Tony:  Is there already a requirement to be able to use the language to specify the sequencing of some messages where the messages are only given a name, URI or some indication of the semantic, but no details?  If not then we should add to the Requirements document.  I have looked but could not identify one precisely.  Such a requirement would support (and be supported by):  2.2 How is a Choreography used?:  1) promote a common understanding between WS participants; and 4.3 CSF Analysis Requirements  2)  A CDL SHOULD be distinguishable from implementation languages.

Steve said he supported the abstract level but was concerned at having both portable and concrete.  He thought the concrete was really just a binding of the portable to Web Services.

The abstract has conditions expressed in English or as a URI, whereas the portable could have precise conditions expressed in, for instance, XPath (where possible - does not include how to resolve internal conditions).

Martin said that there were more than two levels in the Web Service Description Language as there was the abstract level, the binding and also the full deployment information.

Hadrian referred to Table 2 in the specification model overview and commented that there seemed to be a large gap between abstract and portable whereas portable and concrete were close.

Abstract level is aimed at business people and design time,

Portable is aimed at general use and implementers,

Concrete is aimed at being specific for a particular purpose.

It was agreed we need to define the levels precisely so they can be flagged and tests carried out that a description meets the language specification for the claimed level.

Steve suggested colouring the UML diagram, when it becomes available, to show which parts belong to each level.  However, David wasn't sure it would be easy to do that, although appreciating the idea, as much of the difference between the levels was in the degree of information provided with the ‘variables’ -  the precise difference between the levels is in the specification for these variables.

Steve suggested that an example of each level would help and perhaps could be put in the primer.

It was agreed to log the number of levels and their definition as an issue.

NEW ACTION:  Greg to log  the number of levels defined in the language specification and their definition as an issue.

It was also agreed to log Monica's issues into Bugzilla so that they are remembered and discussed.

NEW ACTION:  Greg to log Monica's issues into Bugzilla.

 Liaison Reports/Issues


Monica mentioned that there was a BPSS face-to-face over the next few days in Santa Clara, USA.  If any relevant use cases are raised she will report them back to this group.

Feedback from WSD meeting

Web Service Description Language group

Jeff said that the letter on ‘Features and Properties’ that this group had sent to the Web Service Description Language group was discussed several times at their recent face-to-face meeting and gave rise to spirited debate.  No decision was made as there was both support and opposition, and there will be another debate during the March face-to-face meeting.  However, Features and Properties are back on the agenda again and Jeff felt that currently the majority were in favour with five companies proposing to enhance, four companies opposing and the rest not saying much.




Next meetings

Next Tuesday (10 February 2004). 

The next face-to-face meeting of the group is as part of the W3C Technical Plenary Cannes – Mandelieu, France 1 – 5 March 2004 with the WS-Choreography group meeting on the Monday and Tuesday (1 -2 March 04).


NEW ACTION: editors to revise documents and table of contents according to comments received (0203)

NEW ACTION:  Greg to log  the number of levels defined in the

language specification and their definition as an issue.

NEW ACTION:  Greg to log Monica's issues into Bugzilla.