WS Choreography Conference Call Notes
April 15, 2003
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Chairs |
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Oracle Corporation | |
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Enigmatec Corporation | |
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W3C Staff Contacts |
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Attendees |
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BEA Systems | |
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Cisco Systems Inc | |
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Commerce One | |
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Computer Associates | |
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Enigmatec Corporation | |
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Fujitsu Ltd | |
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Hewlett-Packard | |
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Hitachi, Ltd. | |
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Intalio Inc. | |
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Intalio Inc. | |
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IONA | |
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Nortel Networks | |
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Novell | |
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Novell | |
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Oracle Corporation | |
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SAP AG | |
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SAP AG | |
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SeeBeyond Technology Corporation | |
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Sun Microsystems, Inc. | |
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Sun Microsystems, Inc. | |
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TIBCO Software | |
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Uniform Code Council | |
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W. W. Grainger, Inc. | |
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W. W. Grainger, Inc. | |
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webMethods, Inc. |
Minutes of last meeting approved.
Resubmit use cases.
Not much seen about resubmitting of use cases
Steve asked people who have not submitted to resubmit
Action: Steve will strong arm people (includng himself) who have not submitted their use cases
Editors mailing list
In progress, due to be complete by the end of the week
Dave Chappel, XML Editor Ð Dave Chappel has submitted the email
Carol McDonald (Sun) and Dave Chappel (Sonic Software) would look into hosting a face2face meeting in the future
Carol in progress
David not on the call
Harvesting Use Cases
No progress Open Action: Steve
Chairs to compose tasks for call
No progress Open Action: (Martin/Steve)
Extract requirements from the minutes
Action: Martin
Daniel
Classifications in WSA Ð recorded in the outline of the requirements Ð closed
WS Grainger
Only issue WSG have is getting a decision from the group on dates and time
Several emails received on current date 23-27 June proposed date is bad
Propose 18-20 June instead Ð postpone discussion until the end of the conf call. (see below)
Steve: He needs to understand the timeline for the requirements document so that it can be published. Topic for future call: AGENDA ITEM
Led by Martin Chapman
Submitted reference to doc to IRC (I'm not on IRC)
Use case focuses on what artifacts are required to plug into choreography
Company has process
New partner comes along
What do partner have to do to join in?
Assumes choreography has been pre-defined by bigger company
Two examples:
Car manufacturer with suppliers
Global car reservation system
Common feature is that the owner of the process tells everyone else what to do.
Question:
Do artifacts mean what definitions, interfaces etc are required? They are not design level artifacts.
Non requirement is design time artifacts
Can use the use case to drill down and identify the artifacts
Also focuses on the external aspects and bringing two companies together. The internal artifacts are not exchanged, what can you observe so that you can plug in across company boundaries.
Daniel
Wondering if any information about what goes on behind the curtains is not necessary.
Martin
You only need to define what is on the boundary in order to get the external boundaries to work
Daniel
E.g. Sabre would want to know information about the user and their preferences e.g. for seats, meals
Martin
This is part of the info that is in the interface.
Martin/Daniel
Reach consensus that if info like preferences is in the information then withdraws concern.
Daniel
Examples don't read like use cases they are more like a story board. Can we have a more formal description of them.
Daniel will put out a proposal for formally recording use cases and the problem they are trying to address. Action Daniel
Martin
Use cases are usually about what happens in a real-life scenario this actor does this then another actor does that. No web services implications. They are not UML use cases and more a business scenarios.
Daniel
Thinks UML style use cases are more useful including the systems and the actors interactions.
Martin
My use case covers design time
Decide to take off line
Frank
Talking about producing a standard language for defining choreographies. Need to define the business case very carefully, therefore something that is both business and technical. So far is only business focused, no description of technology used. We are in competition with Microsoft. They have more power than we do.
Any work that the W3C does has to have a clear role in the business community.
It is hard for us to be crisp and clear on what we do Ð Martin agrees.
Shouldn't be scared of Microsoft we are not in competition with them
Steve
Important to hold the line that we are complementary. Everything we have done so far is like this.
David
Should focus on Rosettanet and others and getting them involved.
Frank
David Ð you missed the point. You have the specs written in the WSCL what is their role.
Len
What's a use case, is it design time or a higher level business artifact. The essential idea is that it looks at something outside the boundary and relates to the thing inside the boundary. So use cases can be at various levels of abstraction, from a business system with a workflow to a much more detailed interaction between subsystems. The challenge is that they (the use cases) are all over the map and it might be helpful to refactor them into a specific format so that we can understand the level of abstraction that the use case is at.
Steve
Question? Daniel, we will present a UP based presentation on how to record use cases.
Daniel
Intention is to take advantage of his boss a Use Case expert and plans to use this to help propose a formal approach to defining use cases. Assumes this will be a UP based use case with pre conditions, post conditions, diagram, etc Action Daniel
Len G ??
Need to agree on the content of the use case.
Daniel
We should be able to cross reference the use cases with the requirements when we are done
Martin
Posts to IRC the links to use case work in the WS-I
Can recast second example in the correct format for a "proper use case"
Doesn't know how to describe a design-time use case. Action Will talk with Len offiline.
Martin
Discusses second use case
Retailer offers B2C use case where as stock is depleted, the stock levels go down until a point is reached where the goods get re-ordered to replenish stock levels.
Don't want to do this with a blocking RPC call, but instead come back later when the goods have been shipped. There is an extended asynchronous interaction between the warehouse and the manufacturer that results in the goods being retrieved. Resulting requirements
Long running processes
Correlating messages
Etc.
Steve
The main issue is around time that causes a different approach. Do we encode time into the choreography?
Do we also search for services based on the time they take to run?
Martin
That's part of the idea of the use case. Discussions on the list on timeouts have been useful.
Ed peters
Rosettanet PIPs have specific mention of timeouts as does BPSS
Jean Jacques ??
With current technologies can't query to search on services based on time
Steve
Question, is delivery within a timeframe important
Len (Grainger)
Yes it is important and the relationships are specified contractually
?? Jean
Need to distinguish between a technical timeout and a business timeout
?? Are both out of scope
Technical too low level, business timeout is contractually agreed
Daniel ??
We do need a requirement that exceptions are handled including timeouts
??
One persons exception is another persons message
David
Need to separate the trigger from the message
Frank ??
Do we have guideline for what goes into the solution, e.g. is loose coupled?
Ans. Not yet
Conclusion
Modeling business time is an issue we have to deal with (raised by Steve). Need to spend time on a future conference call. Topic for future call.
Last call was cut off on the issue of ontologies and naming Ð we were swimming with the trout!
Is there a trout repellant.
Martin: We haven't adopted the trout
It should be the bumble bee Ð Steve says they have interesting choreography patterns
Defer to next week as an agenda item. David can't take minutes and discuss at the same time !!
Daniel
Has everyone looked at the Spring Fever edition of the requirements document?
This is the 0.0 version of the document. It's a place to start. Nothing carved in stone. Not normative.
Pay attention to editor's notes
Interesting parts are the abstract and introduction
Section 1.1 is controversial Ð definition of a choreography
Proposed a classification system for use cases in section 1.2
Requirements numbering might not be sequential with gaps because requirements have been dropped
The rest of the document is a place holder
Editors will get text added in.
Wants to know what has been forgotten Ð feedback needed Ð action all
Frank
Is it a use cases or a requirements document?
Daniel Ð its both
Frank
Should we include mission, goal and CSFs.
Martin
Thinks this is a good idea
Daniel
In WSA, used CSF analysis to determine the requirements Ð worked very well for an architecture project
For choreography thought might be better to follow a use case driven choreography
But Frank (and others) think that a CSF approach is useful
Len G
Thinks that doing the CSFs will help us decide what should go in the Use Case.
Frank
Being able to tie back the specification back to the requirements and the CSF will be very useful for driving forward the specification.
Len Gretsky
Agrees this is a good idea
Daniel
Excusing himself from the discussion as he is the editor and will accept decision of the group
Mike Champion
Was not really pleased with the way the CSF worked in the WSA. There was a fair amount of confusion. Would prefer to see it driven more from use cases.
Frank
Use cases don't help tie down the loose ends but is better for exploring the space.
Thinks the WSA was not critical enough of the approach.
Need to understand why it did not work on WSA
David
Can we analyze the use cases to determine requirements and CSFs
Steve
Thinks he agrees with David
What can we do better through using the results of this work
David
Offered to lead the CSF part of the work based on doing similar stuff as a management consultant
Len
Action: Everyone should read the CSF part of the WSA spec to understand what it is about.
Frank
Suggested we should we spend time on CSFs during the F2F
Steve to Daniel
Two minutes to close the topic
Daniel
Please everyone read the document Ð you must suggest alternate text and not just criticize
Martin/Steve: we have to decide the date today to comply the W3C
Melanie, Jeff , Yaron can't make 18-20 June
Location, Grainger, Lake Forest, Illinois. 18-20 June, meeting for 2.5 days until Friday lunch
Motion by Steve to schedule for 18-20 June by Steve: No objections, motion passed
Need volunteers to think about September F2F and let Jeff know. Ideally in Europe.
Look to hold it at SAP in Germany.
Yves to look at holding it in Nice.
Steve to look at an academic place: Edinburgh, St Andrews or Cambridge.
There are also cheap rooms at the Baghdad Hilton Ð Steve.
How about Oz, September is when the Rugby World cup is held Ð Duncan J-W.
June will be hard for Hugo.
Outstanding actions
New actions
Next face to face meeting will be on 18-20 June hosted by W.W Grainger, Lake Forest, Illinois.