Re: [service-orientated-architecture] XAML for Business Process?

[Keith Harrison-Broninski]

Anne Thomas Manes wrote: BPEL is absolutely inappropriate as the base language for WF. BPEL is much too complicated. BPEL works on the assumption that you are invoking services, and that the services already exist -- you don't write the core services in BPEL. WF is a framework that you could use to write the business logic of the core services. A BPEL processor can be built on a foundation of WF. Indeed - all BPEL ever set out to do, back when it was called BPEL4WS, was orchestrate Web services, not to do workflow or business process management proper.  This focus on a particular technology, rather than a business problem, is probably why it's future now looks so black.  It was never a true process language. But neither is WWF.  Standing back from the vast amount of self-congratulatory hype the MS publicity machine is generating, is this a workflow system at all?  To me, it would be better named "Windows Programming System for Dummies".  WWF is not really about workflow, or any other computational problem domain - it is a concurrent execution environment for any form of procedural computer program. Note the procedural.  What MS have given us is a software development environment: Which will never run on any other O/S than Windows Ignores the movement towards object-orientation that started in the 1960s. Welcome back, Visual Basic. WF uses a declarative programming model for expressing business logic. Therefore it needs a declarative programming language -- XAML. (XAML is designed to express business logic as well as UI widgets.) Neither WF nor XAML are "declarative".  Being capable of representation in XML doesn't make something declarative, even if you can write simple property assignments in XAML rather than hiding them in a service call (a feature that some members of this forum might not consider an advantage anyway).  Statements in a declarative language are conditions that assert what the program must do, from which the virtual machine infers how to do it (without the user telling them or even needing to know).  Statements in WWF are nothing like this at all. In fact, the underlying conceptual model of WWF is equivalent not only to Petri nets (the classical "state-transition machine" programming model invented in 1962), but also to BPEL, something that MS tacitly acknowledge by providing a "BPEL Pack" that lets you persist any WWF process with appropriate activities as BPEL. Don't believe everything you read.  Even if it comes from Microsoft, famed for its ethical approach to business. -- All the best Keith http://keith.harrison-broninski.info SPONSORED LINKS Service-oriented architecture Computer monitoring software Free computer monitoring software YAHOO! GROUPS LINKS  Visit your group "service-orientated-architecture" on the web.    To unsubscribe from this group, send an email to:  [EMAIL PROTECTED]    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.