On Apr 27, 2007, at 10:49 AM, Mike Glendinning wrote: > --- In [email protected], Stefan Tilkov > <[EMAIL PROTECTED]> wrote: > > > > I was in a panel discussion at a conference this week, and was > > surprised to notice there's still no consensus about whether or not > a > > process engine (or rather, support for automated BPM) is a "must" > for > > SOA. > > Stefan, > > when you mention BPM, Workflow and BPEL you are covering quite a wide > range of concepts and technologies, perhaps too large for your > question to make any real sense. > I know, but I choose not to care ;-) > At one end of this range you have the definition and management of > long-lived horizontal workflows, usually human-based and with all the > attendant business issues of the process re-engineering fad, etc. In > my view, this is entirely orthogonal to SOA and requires a different > approach and different set of technologies. > I agree this is orthogonal, and this is what I was referring to in my view above. > At the other end you have the implementation of automated, short- > lived vertical workflows, otherwise known as composite services. > These, I think are an essential part of SOA and its unlikely that any > meaningful SOA will not find the need for these kinds of services at > some point. As others have pointed out, composite services can be > implemented in a variety of ways, for example directly in Java or > using a BPEL tool (process engine). But this choice is exactly what > it says - an implementation decision - and is therefore nothing to do > with the SOA itself since one of the major goals of SOA's "loose > coupling" is to separate service interface (or contract) from > implementation: you should not know or care how a services is > implemented. > > Therefore, I think that although a process engine "may" be the right > way to implement composite services in a SOA, this is definitely not > a "must have". This is exactly my opinion (which is a nice coincidence for various reasons ;-))
Stefan > > Regards, > > -Mike Glendinning. > > >
