- From: Ricky Ho <riho@cisco.com>
- Date: Wed, 26 Mar 2003 10:55:38 -0800
- To: "Stephen White" <swhite@SeeBeyond.com>
- Cc: <public-ws-chor@w3.org>
Thanks ! Exactly correct ! At 09:30 AM 3/26/2003 -0800, Stephen White wrote: >I was having trouble following the use case as a text description, so I >made up a couple of diagrams to help me follow the example. There is a >diagram with a 3-party choreography (3Part_Pat-Recp-Doc.jpg) and three >separate diagrams of the individual 2-party choreographies (within >3_2Part_Pat-Recp-Doc.jpg). I am sending in the diagrams to help those like >me who need to see pictures. > >A note about the diagrams: The activities of the three parties are >separated by swimlanes. The solid lines between activities indicate the >sequence of activities for each party. The dashed lines show the flow of >messages between the parties. I numbered the messages as was presented in >the example. The activities within the swimlanes represent only the >interface for that party. Presumably, there are activities that go on >behind the scenes, but are not modeled in the choreography. > >-Steve > >-----Original Message----- >From: Ricky Ho [mailto:riho@cisco.com] >Sent: Tuesday, March 25, 2003 1:46 PM >To: edwink@collaxa.com; jdart@tibco.com >Cc: public-ws-chor@w3.org >Subject: RE: More about the patient/receptionist/doctor use case. > > >Edwin, > > > > > > > In your example, you haven't covered the contract of > > > collaboration between > > > the receptionist and the doctor. After your break down, > > > there is nothing > > > saying that step (1) must happen before step (2). It is > > > possible that a > > > doctor say "I'm available" but then no patient shows up. > > > >I am not sure that I understand your point: > >Are you trying to say that it is important that the patient knows how > >the receptionist query doctors or that once an appointment receipt has > >been generated, the patient might decide not to show up and you want to > >manage the appropriate timeout and release of resources? > >No. The patient doesn't care but the doctor may care. >In a multi-party choreography, this is NOT just the patient's concern, but >also the receptionist as well as the doctor's concern. > > > > > Look at the pre-requisite of "MedicineDelivery" service. It > > > may not be > > > sufficient by just having the Prescription Receipt. What if step (7) > > > hasn't happened. the doctor hasn't told the receptionist to prepare > > > medicine so even though the patient presents the prescription > > > receipt, the receptionist is not going to delivery the medicine. > > > >This is where I think that the notion of responsibility is important. I > >expect the doctor service to do the right thing and issue a valid > >prescription receipt. If the receipt end up being invalid, I can go back > >to the doctor and complain. > >Yes, but how do you express that responsibility in the choreography >definition ? > > > > > Similar argument in "DoctorService", the pre-requisite is not > > > sufficient. What if the doctor hasn't been asked by the receptionist > > > before the patient shows up in his door with the appointment receipt. > > > >Same as previous answer here. The appointment receipt is contractual > >binding. The receptionist is responsible for offering that service. In > >my opinion, micro managing how the service is provided creates > >unecessary complexity and seems going against how business operate > >today. > > > >The point that I was trying to make is NOT that multi-party interactions > >do not exist and should not be modeled. My point is that given the > >business and legal contractual overhead of collaboration, most > >interactions tend to orbit towards bi-party interactions. Those bi-party > >interactions can be interlinked in a very loosely-coupled fashion using > >"typed" contractual documents. > >I agree. I certainly think the majority use cases are bi-party contract. > >Best regards, >Ricky >
Received on Wednesday, 26 March 2003 13:55:49 UTC