Ugo Corda wrote:
Ron,
you say:
>
A standardized modeling vocabulary is very useful; a modeling
vocabulary that omits key concepts (for example, sub-processes) has far
less value.
We
have actually not been talking about omitting the concept of
sub-processes, but rather whether this concept could be modeled with
existing constructs (possibly with minor modifications to existing
syntax).
I think we may be getting to the core of the disagreement here. It is
my assertion that BPEL has no vocabulary for expressing
subprocesses/subfunctions. Instead, it advocates treating them as
services by convention. This is where the rub lies, I suspect.
My
tools argument was not about the tools compensating for functionality
not existing in the language, but rather about making the issue of how
this functionality is actually expressed less relevant.
A fail to see a distinction. Perhaps you can elaborate on this point,
please?
Your
argument that analysts are uncomfortable with a WS-based approach seems
rather weak, given the fact that WS concepts are very aggressively
spreading throughout the industry (so that even pointed headed managers
are quite comfortable talking about Web services today ;-).
It is true that buzzword compliance dictates a certain familiarity with
some WS concepts, especially SOAP.
However, I'm not arguing that analysts are uncomfortable with WS-based
approaches; I'd say they are adding SOA concepts to their bag of
tricks, but they aren't casting aside other tried-and-true concepts in
a rush to treat the universe as nothing but web services. We've all
seen far too many over-sold "silver bullets" to now breathlessly cast
aside everything for the latest acronym du jour!
What I am trying to say is that analysts today have a rich vocabulary
for describing business processes, including ones that are amenable to
automation (executable in our parlance). BPEL omits some important
elements of that vocabulary. That should be of concern to us.
It
would be like saying, 20 years ago, that languages should not have used
OO constructs just because programmers were only comfortable with
functional programming.
Humm. I not sure I buy the analogy. OO was additive -- it added new
concepts and language features to the existing structured programming
model. The case we have in hand is subtractive -- it is removing
concepts, or in some instances attempting to collapse them. Certainly
BPEL is a sparse process language, compared to most others. From the
process point-of-view, web services serve mainly to create a simplified
model of work performers. Secondarily a process can serve as a service
composition mechanism. But I digress: I don't think the analogy with OO
adoption is apt.
-Ron
