Response to Comments on BP Metamodel suggestion

[bha@us.ibm.com]

Hi:

  The following clarifications are in respone to Bob Haugen's comments on
the WPDL (Workflow Process Definition Language) metamodel suggestion.

1. There was NO suggestion to make a wholesale change of the BP Metamodel
with WPDL metamodel. Neither was there any suggestion to accept WPDL as-is.
The suggestion is to look at the Process/Activity/Business Transaction
entities in the BP Metamodel (the top right quadrant of the UML
representation that is currently in circulation) and replace those with
WPDL metamodel entities -- ofcourse this would call for some augmentations
in WPDL to include events and such.

2. Why is this suggestion important? The WPDL is an intermediate process
definition standard between business process modeling tools and workflow
runtimes. So any business process modeling tool, conformant to WPDL, can be
used to generate a business process graph and generate a WPDL output. This
can be then imported to workflow runtimes and further optimized to the
workflow runtime and then executed. This is not just theory but does work
in practice! So by augmenting the WPDL we have a good chance of getting the
ebXML metamodel adopted by a very large community of business
transformation specialists and solution providers. (For those of you who
are interested in playing with WPDL you can visit www.holosofx.com and try
out the WorkflowBPR tool to draw the business process graph and generate
WPDL. Disclaimer: this is just a personal suggestion and neither I nor IBM
is endorsing this product/company)

3. Now let us sort out a few areas of confusion. A business process
typically is at the very top of the stack in a B2B conversation. The
business process choreographs the information interchange. The WPDL like
model expresses this graph. The RosettaNet PIP can be expressed in terms of
such a business process graph. The next layer down the stack is the
information interchange sequence that is part of the business protocol and
triggered by the business process. This can be expressed either using
mechanisms such as the trading partner agreement markup language  (that
begins to address contract like terms and conditions) or directly executed
by a protocol plug-in in any enterprise boundary server. The next layer
down the stack is the document exchange layer where one worries about the
message enveloping and de-enveloping that are part of the message delivery.
Further down is the transport layer that binds the delivery to specific
transport protocol. WPDL is applicable only at the business process level.
THe actual messsage definitions and the information interchange sequence
need not be expressed in WPDL although such elements will constitute the
overall BP metamodel. A metamodel by the way can generate multiple run time
components at deployment time -- it is not one giant executable resulting
from a metamodel that drives B2B conversation!

I want to be clear about the intention for the suggestion. It is NOT to
frame the issue as  "WPDL versus the rest of the world." It was meant to be
contributory to our overall effort in constructing a solid BP metamodel.
Sure, one can use WPDL constructs (with augmentations) to model supply
chains and a variety of e-business problems. I think we want to be able to
do the same with ebXML BP Metamodel. If it builds on prior art  such as
WPDL I think it moves all our efforts that much closer to efficient models
and realizations. I hope we can approach this in that spirit.

My colleague Marc-Thomas Schmidt will be in Brussels to address some of the
technical questions on the WPDL during the workgroup session.

thanks
kumar