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

Unless a role materialises as a concrete thing (say with a wsdl interafce
and some predefined operations),
then I am not sure  what it means to say a role may be used by more than
choreogarphy, aside from the
syntactic name being the same.

Martin.

> -----Original Message-----
> From: Burdett, David [mailto:david.burdett@commerceone.com]
> Sent: Tuesday, June 10, 2003 10:35 AM
> To: 'Assaf Arkin'; 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
>
>
> 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 14:20:52 UTC