Issue 14668: Event-based gateways in choreography should be exclusive (bpmn2-rtf)
Source: NIST (Mr. Conrad Bock, conrad.bock(at)nist.gov)
Nature: Revision
Severity: Significant
Summary: An event-based gateway implies a message is being waited for, but
choreographies can't receive messages, they have no central controller.
One of the participants will have an event-based gateway internally, but
the other will have a exclusive gateway. The choreography can use an
exclusive gateway with no conditions, with the semantics is that exactly
one of the following messages will be sent.

Comments:
From: conrad.bock created: Mon, 13 Jul 2009 15:53:49 -0500 (CDT)
Email from Frank about conditions on exclusive gateways in choreographies:

Hello Conrad, 

In my opinion there is no need to even have data as decision criteria.
There may be a button, that a user presses (request xy..). Of course you
can discuss, that the fact, that a button has been pressed is in itself
data in the system. But it is a different kind of. 

So in the case of two senders there are two users and two buttons.
Whoever presses first sends first. 
Whoever sends second is in a different branch of the choreography.
That's how I understand it.
Resolution: 
Revised Text: 
Actions taken:
November 19, 2009: received issue
Discussion: 
The FTF Team is not able to allocate time to reach resolution, so we will defer this issue.
Disposition: Deferred
End of Annotations:=====
sed gateways in choreography should be exclusive

##Source: NIST (Conrad Bock, conrad.bock@nist.gov)
##Original Issue: http://www.osoa.org/jira/browse/BPMN-565
##Original Info: (Severity: Significant - Nature: Revision)

An event-based gateway implies a message is being waited for, but
choreographies can't receive messages, they have no central controller.
One of the participants will have an event-based gateway internally, but
the other will have a exclusive gateway. The choreography can use an
exclusive gateway with no conditions, with the semantics is that exactly
one of the following messages will be sent.

Comments:
From: conrad.bock created: Mon, 13 Jul 2009 15:53:49 -0500 (CDT)
Email from Frank about conditions on exclusive gateways in choreographies:

Hello Conrad, 

In my opinion there is no need to even have data as decision criteria.
There may be a button, that a user presses (request xy..). Of course you
can discuss, that the fact, that a button has been pressed is in itself
data in the system. But it is a different kind of. 

So in the case of two senders there are two users and two buttons.
Whoever presses first sends first. 
Whoever sends second is in a different branch of the choreography.
That's how I understand it. 

Best Regards,
 Frank