- From: Dale Moberg <dmoberg@us.axway.com>
- Date: Mon, 12 Feb 2007 11:32:49 -0700
- To: "Steve Ross-Talbot" <steve@pi4tech.com>, "Monica J. Martin" <monica.martin@sun.com>
- Cc: "WS-Choreography List" <public-ws-chor@w3.org>
- Message-ID: <97085FEE4C8BDB4AB6FA3E770EBC79BBBE5AB3@mail1.cyclonecommerce.com>
Steve Ross Talbot writes: > I got the minutes from our last ISO WG4 meeting. Included is the > following: > Q: How does the choreography compare with that in WS-CDL? > A: The choreographies are not very different, but if you port BPSS > into CDL a lot of material is not carried over. However the BPSS > choreography was developed empirically from actual projects and is not > based on Pi Calculus or any other academic body of thought. > DaleMoberg>> Both Monica Martin and I responded to this question and we mentioned (among other things) the following as contributing to BPSS UML and UNCEFACT's UMM and BPMN (extensions were used in diagrams) Use cases from UCCNet, RosettaNet, Twist, and other Vertical SDOs. I mentioned that the UML 2.0 Sequence Diagram with the Combined Fragment enhancements (for alternatives, options, par, break, and so forth) is similar in expressive power with respect to choreography. There was little explicit consideration of pi-calculus in BPSS development. This comment is not meant to be pejorative of either BPSS or pi-calculus. I did indicate my opinion that viewing business collaboration as a distributed computational process, while possible, was not expressed in the specification. > What specifically is lost when xlating from BPSS to WS-CDL? There has been no specific investigations on expressive powers, but this comment was probably in the context of mentioning that the business contract documented in a BPSS M1-level description is not only the messages exchanged together with the "logic" of the exchange, but also many quality of service parameters pertaining to the process. I do not think that these features have been a focus of WS-CDL at least when I last reviewed it. That would be understandable because these features pertain to aspects of the business contract that are not primarily choreographical. The various timers over "stretches" of message exchange that pertain to "time to perform" or "time to acknowledge" are such features. Likewise, the parameters pertaining to QOS of reliability or data confidentiality or data origin authentication are such QOS aspects of the contract. So these components of the model drop out. A similar situation would be found in maps to UML or BPDM. The requirements on BPSS documenting a business process, and the abstraction level enforced, are distinctive. I guessed that there were probably no choreographic features that would necessarily be lost in forming a WS-CDL document. Possibly you would need to include, in the BPSS document, some information in the (BPSS optional) OperationMapping elements that say how to connect a BusinessTransactionActivity and its referenced BusinessDocuments to a WS portType/interface's Operation and messages. This matter depends on how "abstract" the connection to a wsdl defined WS can be. I will let Monica who knows both specifications comment on how easy a translation would be that did not contain OperationMapping. > > What would be lost in xlating from WS-CDL to BPSS? > We did not discuss this direction of translation. I am uncertain how the rest of the remarks pertain to anything we stated in our review of BPSS. I would note that both UML and UMM (which are formalisms of course) did provide foundations for constructing BPSS and its schema.
Received on Monday, 12 February 2007 18:32:58 UTC