BPEL questions: Q & Use Cases: UUID?

[LI Yanming / FTR&D / US <yanming.li@rd.francetelecom.com>]

Title: BPEL questions: Q & Use Cases: UUID?

Hi All,
There was a previous discussion around using UUID for process instance correlation. Here I would like to present two use cases which show that a UUID approach might be necessary for correlating process instances.

I). I have a collaboration process which involves A (a portal, process caller), B (actual process), C (user which email account).

The scenario work like this:
 1. A invokes process B
 2. B sends email to C
 3. C reply email to B
 4. B continue
In step 2 & 3, B and C correlate each other through the email's subject. In order to ensure C's reply to trigger the correct instance of B's, a unique identifier is required. In this case, I see the need for a unique process ID. If we do not want to use process UUID, we have to bother to create another unique ID for this type of correlation.

Currently, BPEL allow "A" to use something like SSN(social security number) to correlate with an instance of process "B", but this type of mechanism won't work between "B" and "C". In the case that "A" send several requests using the same "SSN", "C" will receive same subject field for all

corresponding requests, its rely messages can trigger any one of B's pending instances.

Because "C" can be any non-BPEL asynchronous web services which require correlation with an invoking process, like "C". The general question is the how do you provide correlation in this case if we do not use process UUID?

II) The second scenario is more related to monitoring:
We still assume that we have three processes, A, B, and C, which are distributed among partner1, partner2, partner3 accordingly. If we want to monitor which instance of "A" is associated with which instance of "B", and which instance of "B" is associated with which instance of "C",  It seems that a process UUID is the only way to standardize this type of monitoring.

I am not sure if these two scenarios are exact fits for BPEL, but they did come from some of my case studies.

Comments are welcome!!
thanks
Yanming