Issue: Levels or types of Choreography description

Dear Colleagues,

The first draft of the proposed Choreography description language contained
the definition of three levels of description: abstract, portable and
concrete.  Personally I had some sympathy with this notion, though it was
debated as to how many levels were required and what the precise definition
of each should be.

As the notion of levels has been removed completely from the current editors
draft, I would like to raise an issue on this.

Levels or types of Choreography description:  I suggest that we should
specify at least two levels or types of Choreography description.

One level could be called abstract or business process oriented or some
such.  It would support focus on the definition of the business exchanges.
It would specify the allowed sequencing of messages and the nature of each
message.  It would not have to provide a precise specification (/schema) for
each message nor how each message was to be transported.  This it would
allow agreement of the basic business 'protocol' but would be insufficient
to enable interoperability on its own.

Another level or type of Choreography description would provide a precise
specification and schema for each message and how each message was to be
transported.  It would thus be a basis for interoperation or at least
provide the interoperability specification of the upper layers of the
protocol stack.

Best Regards     Tony
A M Fletcher
Home: 35, Wimborne Avenue, IPSWICH  IP3  8QW
Tel: +44 (0) 1473 729537   Mobile: +44 (0) 7801 948219
 amfletcher@iee.org     (also tony.fletcher@talk21.com  &
tony_fletcher@btopenworld.com)