Minutes W3C WS Choreography WG con call held on 29th July 2003, 1pm PDT.


Role Call
Confirm scribe

The following is a list of recent scribes (in order): Tony, Fletcher, Jim Hendler, Kevin Liu, Tony Fletcher, Jon Dart, David Burdett, 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, Leonard Greski, Ed Peters, Greg Ritzinger, Daniel Austin, Peter Furniss, Jim Hendler

Approve minutes
             Minutes 22nd July 2003


Action Item Review

Last week: 17 ongoing action items and 3 new actions from last week. 

This week: 7 ongoing action items and 5 new actions from last week.


Standing tracking items (a section designed to ensure that longer running items are properly tracked)
Requirements (progress/review)
Mission Statement
CSF Analysis
Use cases
Requirements listing
Issue tracking (progress/review)
Major issues to report
Task forces (progress/review)
Task list


Threads (on the archive not covered elsewhere in the agenda
Composition (the atoms) or Where do we ground?
Can we get consensus on this?
Choreography protocol
Choreography State Definition
Proposed text for Choreography concepts
Decision Points Requirement Proposals


Role Call:




Steve Ross-Talbot


 Martin Chapman


W3C Staff Contacts


Yves Lafon









Mayilraj Krishnan

Cisco Systems Inc


David Burdett

Commerce One


Yoko Seki

Hitachi, Ltd.


Eunju Kim

National Computerization Agency


Abbie Barbir

Nortel Networks


Greg Ritzinger



Kevin Liu



Ugo Corda

SeeBeyond Technology Corporation


Monica Martin

Sun Microsystems, Inc.


Jon Dart

TIBCO Software


Ed Peters

webMethods, Inc.

Jean-Jacques Dubray





Yaron Goland

BEA Systems

Anthony Fletcher

Choreology Ltd

Paul Lipton

Computer Associates

Fred Cummins


Michael Champion

Software AG

Carol McDonald

Sun Microsystems, Inc.

Daniel Austin

W. W. Grainger, Inc.




Appointment of scribe:


Monica Martin (Sun Microsystems), kindly volunteered to scribe for the meeting.


The following is a list of recent scribes (in order):Tony Fletcher, Kevin Liu, Tony Fletcher, Jon Dart, David Burdett, 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, Leonard Greski, Ed Peters, Greg Ritzinger, Daniel Austin, Peter Furniss, Jim Hendler




Minutes Approval

Minutes 22nd July Conf Call were approved. <NOTE CHECK URI>

Action Item Review

Last week: 17 ongoing action items and 3 new actions from last week. 

This week: 7 ongoing action items and 5 new actions from last week (marked with a *).



ACTION: Chairs, Oversee the organisation of the task forces.  ONGOING

ACTION: Martin to track back through past minutes for issues and put into Bugzilla. ONGOING

ACTION*: SRT to contact Alastair Barros with a vew to DTSC hosting the W3C Choreography F2F meeting in Melbourne Australia in December 2003. DONE – they will host.

ACTION*: Chairs (SRT/Chapman) to put on the agenda for 2nd September the following item:

            Burdett ML, the extent to which it meets the requirements and the extent to which the requirements are reasonable.


ACTION: Alistair (Barros) will develop a use case / scenario for this broadcast use case. ONGOING

ACTION: David Burdett to provide a design collaboration use case PENDING

ACTION: Martin to propose text for call-back use case. ONGOING


ACTION: David Burdett action on verifying and reporting on the legal aspects of Burdett ML. ONGOING

            ACTION: David Burdett reported that he should have a resolution by next week - cover next week. ONGOING

            LATEST: Burdett - IPR copies provided to chairs; Burdett will post to the mailing list.

ACTION*: DB to produce a commentary on how Burdett ML meets (or not) the current requirements.

            LATEST: Ongoing to determine if this meets our requirements and identify gaps. Analysis paper will be finished by David Burdett prior to the September meeting and he will try to post beforehand.


ACTION*: SRT to send mail to the Semantics tag as to what he is looking for to initiate the discussion on semantics in the WS-Choreography language.

            LATEST (NEW ACTION): SRT Brought semantics question to the TAG. On chairs coordination call, he asked about semantics for/of choreography. A new Semantic Web Services Interest Group is being formed in about one month. Issue will be sent to that group when it is formed.

ACTION*: SRT to  put semantics on to the issues list.


Standing items




SRT: Requirements document to publish as a working draft.

Chapman: Publish draft.

Dart: Concerns about rough nature of the document, BEA use case, and mapping between use cases and requirements.

SRT: Agrees the document is in a rough state. Many players have provided

comments. Document is 'work in progress' and a 'heartbeat.' Document has already been published to the public list (includes non-members).

Chapman: Suggest we publish. Indicate this is a rough draft.

SRT: Move to publish.

Chapman: What does it mean to publish [the mechanics of publishing]?

Yves: Build document so it looks like a working draft.

SRT: Critical Success Factor analysis must be done.

Chapman: Need to place mission statement in the document.

Dart: Does the mission statement belong in this document?

SRT: CSF analysis is derived from the mission statement.

NOTE: Mission statement should be in the next rev of the document along with a refinement of use cases.

Issues tracking

Nothing further to report

Task forces

Ritzinger: Wishes to join Task Force #2.


Composition (the atoms) or Where do we ground?

SRT: Composition definition is still not grounded. Upper bounds are understood in looking at mission statement.

Chapman: WSA discussed MEPs yesterday and how they relate to choreography. Choreography is not an MEP (which is generic). The choreography definition uses application semantics and use one or more MEP. Choreography doesn't name MEPs, according to WSA. Whether we agree is another story.

Burdett: What about RM? MEP are semantic neutral.  Need to have choreography to have some quality of delivery.

Dart: These are not application level constructs. Existing WSDL 1.1 MEP show

how source-destination interact at the wire level to achieve exchange.

Chapman: MEP used to describe PO with req-response pattern.

Dart: MEP doesn't address po request-ack-po response though.

Burdett: What do we mean by application level?

JJD: No absolute conclusion if we need MEP or not.  Isn't this a design practice? Encapsulation is important here. When you have parallel occurrences, this requires more from the choreography.

Chapman: Choreography can use any number of MEP. Choreography uses the MEP concept.

JJD: Don't need MEP to make choreography successful.

SRT: If you can compose protocol choreographies (MEP), can you compose those?

Chapman: There is not in WSDL and SOAP, but will be handled in the choreography.

SRT: Choreography has lower bounds that includes MEP; sets upper bound for SOAP and WSDL.

Chapman: CDL would use req-response MEP pattern.

Burdett: Choreography includes pattern of sequences of message exchange and includes semantics.

(NOT SURE ABOUT THIS, WHAT IS SDL) Chapman: In WSA, no expectation that Choreography will define a MEP. SDL doesn't want to depend on Choreography to define the MEP.

Burdett: In theory, Choreography could be able to define a MEP.

JJD: Don't want WSDL to recreate Choreography language.

Burdett: Describe an MEP using a Choreography or interface for Choreography to MEP definitions in a lower bounds.

Chapman: Question is if you can you use a choreography description language to define an MEP?

SRT: Leaning towards using the MEP.

SRT/Chapman: There seems to be agreement that our lower boundary is WSDL 1.2 where we reuse MEP patterns rather than have a requirement on the language that allows it to be described.

Dart: Are there use cases that say that WSDL 1.2 can support or must be extended  to support?

JJD: Choreography will automatically will MEP definition language.

Chapman: That depends.  Use of template choreographies supports JJD view. If not, perhaps not.

JJD: Agrees.

SRT: What about use case that suggests this - use case 1, client/server? This is not a strong use case.

(ANYONE CLAIM THIS STMT)????: CDL use case makes reference to the ability to use RM (refers to this as a

choreography). Semantic information is included in this although it is not application specific.

Dart: Don't do RM with MEP. Don't choreography and MEP co-exist?

Choreography protocol

Chapman: Consider requirements where participants can be dynamic.  Generic protocol must exist to allow us to communicate the choreography lifecycle  events that can attach a participant to a role in a choreography.

Burdett: Internal rules influence this participation.

Chapman: Do we need it? Do we use the choreography to define it?

SRT: Idea of inviting needs to be discussed further.  Lipton, at a F2F, talked

to provisioning desks or McCabe patient use case.  Someone passes the capability for two parties to speak with one another.

Martin: Is this a proxy?

SRT: Need to get this into the requirements document - identify what lifecycle

events are applicable.

Chapman: Log an issue to say do we need a choreography protocol use case. Requirements exist in the document right now.

Choreography and state

Burdett: Only exists in roles who participate. Total state and query everyone to see what state they are in.

Chapman: Because of distributed nature, go to roles and ask what state do you think that you are in? This leads into choreography protocol discussion.

SRT: What happens if Choreography suspends and the web services do not?

Chapman: Web services can't receive messages within that suspended choreography.

SRT: Are state of definition of choreography and the state of the executing web services different? Elicit requirements for synchronization.

JJD: Need to know start and end state.

Chapman: Web service exists with a WSDL definition. Choreography binds to it. What if another party that doesn't abide by choreography definition wants to the use the web service?

Burdett: One web services can being used within multiple choreographies or outside of a choreography.

SRT: Choreography runs as a proxy and it is monitoring message traffic against a choreography.  Concurrency guard exists in front of the web service. What binds choreography to a web service?

JJD: Do you assume that as soon as you have a choreography, the web service is stateful?

SRT: Shelve discussion today and discuss as a mail list and F2F item. Leave other items for future discussion.

Any other Business

Informing WS-BPEL of publication of Requirements Document

Chapman: WS-BPEL use case subgroup met yesterday; I asked about liaison with WS-Choreography. What about our use case development and their usage scenario efforts?

SRT: Publish document with use cases, including to BPEL subgroups. Notify WS-BPEL of the draft document release.

Dart: What about different IPR concern?

SRT: Encourage them to look at document.


Summary of Issues (2 from previous meeting to be logged)

ISSUE:What do we mean by semantics of web services and what are they for.

ISSUE:our time lines are constrained by the Web Service description language progress.

NEW ISSUE: We need a choreography protocol use case.


Next meeting will be 2 September 2003.

New Action Items

NEW ACTION: SRT to send issue to new Semantics Web Services Interest Group.

NEW ACTION: Yves to provide format for draft publication.

NEW ACTION: Greg to send email to members asking for volunteers to own issues.

NEW ACTION: SRT to write a use case for a choreography protocol.

NEW ACTION: SRT will write an email to tell WS-BPEL we have published the draft document.