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RE: Relationship cardinalities (was ... RE: Requirements: Decisio n Po ints Requirement Proposals

From: Burdett, David <david.burdett@commerceone.com>
Date: Tue, 10 Jun 2003 10:35:25 -0700
Message-ID: <C1E0143CD365A445A4417083BF6F42CC053D1B90@C1plenaexm07.commerceone.com>
To: "'Assaf Arkin'" <arkin@intalio.com>, "Burdett, David" <david.burdett@commerceone.com>
Cc: "'Martin Chapman'" <martin.chapman@oracle.com>, "'Jean-Jacques Dubray'" <jjd@eigner.com>, "'Yaron Y. Goland'" <ygoland@bea.com>, "'WS Chor Public'" <public-ws-chor@w3.org>

Assaf said ...

>>>I assume what you mean by same role is not the fact that both
choreographies choose to call it 'buyer', but the fact that in both of them
the buyer would be able to act in the same way against the seller. <<<
I really mean that a buyer can act in *different* ways with a seller, i.e.
different choreographies, for the same purpose, e.g. placing an order.

>>>In that case, would it make more sense to define the buyer's participant
and then create two choreographies using that reusable definition?<<<

I'm not sure what you mean by buyer's participant. I really think that you
need to define the roles and then identify the role being taken by a
participant in an instance of a choreography.

Does the following agree with your thinking?
1. A participant (or party) is an organization or business that suppports
one or more choreographies (e.g. for different ways of doing business with
partners)
2. A party can take many roles, e.g buyer, seller, etc
3. A role can be taken by many parties, e.g many businesses can be a buyer
4. Choreography definitions are designed to meet some useful "purpose" (e.g.
place an order)
5. More than one choreography can exist that meets the same "purpose", e.g.
there is more than one choreography for placing an order
6. A choreography involves two or more roles, e.g. a buyer, seller, etc
7. The roles are depend on the "purpose" of the choreography rather than the
individual choreography. e.g. you always have a buyer and a seller when
placing an order irrespective of the actual choreography being used.
8. Therefore the same roles may be used by more than one choreography.

Thoughts?

David

-----Original Message-----
From: Assaf Arkin [mailto:arkin@intalio.com]
Sent: Monday, June 09, 2003 7:33 PM
To: Burdett, David
Cc: 'Martin Chapman'; 'Jean-Jacques Dubray'; 'Yaron Y. Goland'; 'WS Chor
Public'
Subject: Re: Relationship cardinalities (was ... RE: Requirements:
Decisio n Po ints Requirement Proposals


I assume what you mean by same role is not the fact that both 
choreographies choose to call it 'buyer', but the fact that in both of 
them the buyer would be able to act in the same way against the seller. 
Am I correct?

In that case, would it make more sense to define the buyer's participant 
and then create two choreographies using that reusable definition?

arkin


Burdett, David wrote:

>Assaf
>
>Here are two example choreographies with the same identical roles.
>
>The first does not allow cancelation of the order once it has been
accepted.
>
>Choreography One
>BUYER             SELLER
>1. Order ---------->
>Either ...
>2.  <------------ Order Response
>... or ...
>3.  <------------ Error Response
>
>The second does allow cancellation or chances after acceptance
>
>Choreography Two
>BUYER             SELLER
>1. Order ---------->
>Either ...
>2.  <------------ Order Response
>... or ...
>3.  <------------ Error Response
>If Order Response received then, at Buyer's discretion, either ...
>4. Change Order ---->
>5.  <------------ Change Order Response
>... or ...
>6. Cancel Order ---->
>7.  <------------ Cancel Order Response
>If Change Order Response received, and at Buyer's discretion then repeat
>from step 4.
>
>These choreographies are different but the roles (and often the messages)
>are identical.
>
>David
>
>  
>
Received on Tuesday, 10 June 2003 13:35:27 GMT

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