Refactoring/reorganizing choreography constructs for ebBP 2.0

["Dale Moberg" <dmoberg@cyclonecommerce.com>]

Hi,

Monica suggested that we begin discussion of some reorganizations that I
have been developing to the BPSS choreography constructs. 

I am including a first discussion document for refactoring Decision,
Fork, Join, Transition, Start, Success, Failure.
The schema changes are incomplete but will be sent when they become more
stable.

Basic procedure so far is: 
1. Follow UML Activity Diagram and Statechart Diagram for choreography. 
2. Try to blend in BPSS constructs, mainly confining the core concepts
to the States (They are BTAs fundamentally).  

This reflects my belief that the core concepts (BTs, UNCITRAL, signals)
are what is most distinctive in BPSS, while the choreography is really a
commodity scaffolding. Mostly the UML models in BPSS 1.x versions can
stay the same so far.

My intent has to make the BPSS easier to implement.

The main incompleteness remaining is with nesting (no longer done with
Transition) and CA (and OA). What I hope to propose is a way in which
these complex state constructs can have their "return" statuses which I
am calling ConditionGuard Values. The initial attempt is to add a
Returns construct that specifies which, if any, of these statuses from
the BinaryCollaboration or nested BT percolates back. This allows
flexible semantics, ranging from "ignore all subordinate results" to
test whether to transition to Success or Failure with respect to these
values.
I think that conforms to the semantics we now have (which has no real
syntax associated with it). Following this,
all that remains is to add in the Role binding constructs as needed.

<xsd:simpleType name="ConditionGuardValue">
		<xsd:restriction base="xsd:NMTOKEN">
			<xsd:enumeration value="ProtocolSuccess"/>
			<xsd:enumeration value="AnyProtocolFailure"/>
			<xsd:enumeration value="RequestReceiptFailure"/>
			<xsd:enumeration
value="RequestAcceptanceFailure"/>
			<xsd:enumeration
value="ResponseReceiptFailure"/>
			<xsd:enumeration
value="ResponseAcceptanceFailure"/>
			<xsd:enumeration value="SignalTimeout"/>
			<xsd:enumeration value="ResponseTimeout"/>
			<xsd:enumeration value="BusinessSuccess"/>
			<xsd:enumeration value="BusinessFailure"/>
			<xsd:enumeration value="Success"/>
			<xsd:enumeration value="Failure"/>
		</xsd:restriction>
	</xsd:simpleType>

Refactoring the BPSS choreography constructs.doc