Execution or modeling? Was: [wsbpel] implicite links of the runtimeengine (was: Implicit <sequence> macro)

[Assaf Arkin <arkin@intalio.com>]

Frank Leymann wrote:

>...which brings up another important point:  Having completely separate
>languages for "business domain experts" is not a good idea because it will
>result in all the known problems of transforming this language to BPEL.
>While this is already complicated, this mapping has to be bijective because
>of monitoring and analyzing the processes:  The other lesson I learned from
>customers is that they want to monitor the processes and want to get
>analysis results in terms of their original model!  Thus, whenever you
>re-write a model defined by a business domain expert into BPEL and you use
>a BPEL engine to monitor your running processes and collect historical data
>for analysis, you must transform the monitoring/analysis results back to
>the business domain expert's variant. Damned complicated!  Thus, I would
>strongly recommend that the business domain expert's language is a subset
>of BPEL in terms of control structures, data aspects etc but enriched by
>business relevant information like resources, costs etc which is needed for
>simulation, for example, before you set a process into production. But I
>consider such latter extensions out of scope of what we strive to achieve
>in our TC.
>  
>
Based on my experience I second everything you said above. It is much 
more efficient if the language used for the business modeling is based 
on the execution language with a additional extensions. Sufficient that 
we have some mechanism to allow this form of extensions to be added. 
(Which also means extensions have to be a requirement for the specification)

However, for the language to allow that type of usage, where users can 
monitor/analyize/simulate "in terms of their oridinal model", the 
language must be able to capture that model, whatever it is. It may do 
so accidentally inspite of the fact that no such requirement exists. It 
may be easier for all of us, though, if we recognize such requirements 
up front and work to address them.

So far I've been hearing that modeling is out of scope, but I've also 
heard too many requirements that I understand to be derived from 
modeling (specifically the use of <sequence>), so I'm utterly confused. 
Can you clarify for me what is the intended usage of BPEL? Is this 
something the TC needs to vote on?

arkin

>Regards,
>Frank
>  
>