W3C home > Mailing lists > Public > public-ws-chor@w3.org > June 2003

Re: Requirements: Decision Points Requirement Proposals

From: Assaf Arkin <arkin@intalio.com>
Date: Wed, 04 Jun 2003 22:42:04 -0700
Message-ID: <3EDED82C.5000103@intalio.com>
To: "Yaron Y. Goland" <ygoland@bea.com>
CC: WS Chor Public <public-ws-chor@w3.org>

I like it. I do have a few minor comments, though, with suggested text 
where applicable.

Yaron Y. Goland wrote:

>I propose the following requirements be added to the requirements document:
>
>The WS-Chor choreography description format MUST provide mechanisms to
>enable a choreography to specify that a process in a particular role MUST
>send zero, one or more messages from a statically defined set of messages in
>parallel, serial or any combination of the two.
>  
>
What about iterations?

>The WS-Chor choreography description format MUST be able to describe
>decision points where a process in a particular role MAY send zero, one or
>more messages from a statically defined set of messages in parallel, serial
>or any combination of the two.
>  
>
Not sure what the difference is from above. Whould it be just easier to 
say something like "parallel, serial, exclusively"?

>The WS-Chor choreography description format MUST be able to describe who is
>to receive a message by referencing their role.
>  
>
"By referencing their role" is too restrictive. Perhaps the role would 
reference the messages it expects to receive, or they would be listed in 
the same container, etc. Can we just say something like "identify the 
role that will receive a message"?

>The WS-Chor choreography description format MUST NOT require that the logic
>used by a sender in a decision point to decide how to act be exposed in the
>choreography.
>  
>
Contrary to what may have been assumed, I +1 that.

>The WS-Chor choreography description format MUST enable the annotation of
>all actions with human readable descriptions.
>
I would also add that the choreography description format MUST enable 
the naming of all actions and decision points such that they could be 
referenced from other specifications (e.g. an RDF-based specification 
may say interesting things about them).

>The WS-Chor choreography description format MUST provide an abstract
>mechanism where by the logic used to make a decision at a decision point can
>be expressed through reference to a WSBPEL abstract or executable process or
>similar machine readable logic.
>
I'm not sure I understand this, or perhaps we're using the term decision 
point differently. More clarification would help.

We should change the language such that the choreography doesn't have to 
reference the BPEL, but the BPEL can reference the choreography. That 
would allow me to come up with two different BPEL's for the same 
choreography.

And, of course, this assumes we can even reference BPEL in a normative 
way. I suppose at some point we'll bite the bullet and take a vote on this.

>
>The WS-Chor choreography description format base specification MUST NOT
>specify bindings for the abstract mechanism used to reference machine
>readable logic, rather extension specifications on top of the base
>specification MUST be used.
>
I am absolutely not clear what this last requirement says. What is an 
abstract mechanism used to reference machine readable logic? In fact, 
what is machine readable logic? The first requirement suggests machine 
readable logic. Also, I suggest the text say "specify concrete binding" 
and also allow referencing to be used as alternative to extension 
specifications (in the same way you can reference a WSDL and don't have 
to explicitly extend it just to say something about it).

arkin

>
>I would appreciate it if objections to these requirements were stated in the
>form of alternate proposals. It's easy to say why something is wrong, it's a
>lot harder to spend the time to specify what is right.
>
>		Yaron
>  
>
Received on Thursday, 5 June 2003 01:42:35 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Saturday, 18 December 2010 01:00:21 GMT