RE: [wsbpel] implicite links of the runtime engine (was: Implicit <sequence> macro)

["Maciej Szefler" <mbs@fivesight.com>]

Tony Andrews wrote:
> Wrt abstract processes, I believe what you most often are 
> interested in
> is whether a system of (two or more) abstract processes connected in a
> specified way will communicate without getting "stuck" (i.e.
> dead-locked) under all conditions (timeouts, error cases, etc).
> Bisimilarity isn't relevant for this scenario.
True, this scenario amounts to deadlock detection for a composite process consisting of the two abstract processes. This is not the case I was thinking of but it certainly seems useful. Although, I expect it won't be as common as the case below: I simply don't see business partners producing abstract processes that they then check for compatibility. The more likely scenario is that one partner will publish an abstract process definition that is expected (lets call this partner "WallMart"), while all other partners (lets call them "Small Suppliers") will have to verify that their processes conform to the requirement (the case below).

> Another question that will be interesting is whether an executable
> process "conforms to" an abstract process that specifies some desired
> behavior. In this case, bisimilarity is too strong a 
> requirement because
> an implementation may be in what one would think of informally as
> conformance without actually being bisimilar to the specification. The
> notion of "refinement", which can be stated in a completely rigorous
> way, better suits the desired relationship in this case.
This is the use case I was thinking of and see as being the common one. Althought it seems that the example I gave supports your conclusion that bismiliarity is too strong of a requirement, the original premise (that the abstract/concrete processes pair is "executed" by some machine to determine conformance) remains the same.   

-Maciej