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RE: Terminology - What is a process? Was: Internal processes an d/or external choreographies (was RE: Ev ents and States ...

From: Burdett, David <david.burdett@commerceone.com>
Date: Mon, 14 Apr 2003 09:43:30 -0700
Message-ID: <C1E0143CD365A445A4417083BF6F42CC053D1999@C1plenaexm07.commerceone.com>
To: "'Howard N Smith'" <howard.smith@ontology.org>, public-ws-chor@w3.org

Howard

You make very good points that I just about completely agree with. However,
at the end you ask ...

>>>Is there anything in this abstract "choregraphy" space that is NOT a 
process, that cannot be "described" using process calculus?<<<

I think that the answer to your question is quite possibly "no" and that a
pi-calculus approach would deliver the results we need. The way I think we
determine the answer to this question is by checking how well and *simply*
pi-calculus can meet the requirements.

This makes me think that perhaps we are getting a bit too far ahead of
ourselves and we should focus on the requirements of the solution and in
parallel give some of us folks who do not understand pi-calculus very well,
an opportunity to catch up.

David

-----Original Message-----
From: Howard N Smith [mailto:howard.smith@ontology.org]
Sent: Monday, April 14, 2003 7:07 AM
To: public-ws-chor@w3.org
Subject: Terminology - What is a process? Was: Internal processes and/or
external choreographies (was RE: Ev ents and States ...



David,

You made a couple of remark which I'd like to comment upon:

You said:
 >1. I don't think I would call it "process buyerSeller" as buyer and 
seller are roles and they can have more than one choreography between them. 
I also like the word Choreography >rather than process (as you describe), 
so perhaps a better name would be something like "Choreography 
orderManagement".

and:
 >2. Following on in the same theme, using "process seller" and "process 
buyer" is ambiguous as you will have more than one process at the buyer and 
seller. So how about "process >acceptOrder" and "process placeOrder" where 
each has a property that identifies the role which performs the process 
giving you: "process acceptOrder, role seller" and "proccess placeOrder, 
role buyer".

For the "process calculus people" in the group, everything is a process, 
even the humble integer. (I think that was what Assaf just naturally did). 
In the pi-calculus,
everything is a process - formally. This group, and the industry at large, 
may have started to use the word "choreography" but the term has no basis 
in any
previously published theory, and hence, everyone is using it and defining 
it differently. Similarly, to process calculus people, the seller and the 
buyer are
also processes. In BPM as used in CSC, processes participate in processes. 
The result is also a process.

This "everything is a process" position that process calculus people take 
is in fact quite real. It is the same position taken by object people in 
object systems.
CSC defines BPM as really a new technology, based on processes. It depends 
upon implementations, which we call process virtual machines. The
commonplace
language we used in our book, BPM: The Third Wave, to explain this to the 
world at large is to talk about "first class citizens" in computing. Every 
technology
has a conceptual center, sometimes defined very formally and sometimes less 
so. To see what I mean here are a few first class citizens:

- COBOL, the report
- C, the pointer, function
- Java, the object
- EDI, the business element
- XML, the tag
- RDBMS, SQL, tuple, key
- EAI, application interface
- workflow, resource, task, case

etc etc ... realise this is rough, but you get the idea ...

The reason we identify the process as a new "first class citizen" is 
because in BPM process is not a byproduct of another stack of technology,
but the central entity around which all computation and communication 
occurs. This is what gives BPM its ability to manipulate process, as RDBMS
does relational data. It is what gives BPM its expressiveness in defining 
sophisticated meta-process models that adhere to other process semantics,
for example:

- project plans, schedules
- B2B PIPs
- workflow patterns, task allocation
- collaboration patterns (votes, polls, committments etc)
- supply chain models
- other process languages

It is what gives BPM it's completeness. What we have been looking for at 
BPMI.org and CSC, is a new first class citizen that can express
many of the others, so that we can manage them as processes. A question 
that comes to my mind is:

- Is there anything in this abstract "choregraphy" space that is NOT a 
process, that cannot be "described" using process calculus?

Thoughts?

Howard


---

New Book - Business Process Management: The Third Wave
www.bpm3.com

Howard Smith/CSC/BPMI.org
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Received on Monday, 14 April 2003 12:43:37 UTC

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