rules engine, bpm, esb, msg'ing - functionality overlap?

[hanasakijiji]

This is a business / architectural question - not necessarily a technical one.

Looking for a paper/whitepaper etc discussing how the three of these all work together in an enterprise environment.

As far as I can tell:

Messaging gives an implementation under the JMS API and perhaps an adapter to something like IBM MQ

ESB gives webservices and often, not though not exclusively, a XML/SOAP layer on top of msg'ing. It also gives transformations, ACID transactions and a process flow (maybe session beans or maybe a scripting language like IBM broker)

BPM gives a process flow with ACID transactions and a cool GUI for modeling the flow. A primary language used for BPM modeling is XML for BPEL

A rules engine also models a business process. It can be a java lib called by a session bean or the rules can be exposed as webservices from their own 'container' like ILOG and others.

So, what processes go in the rules engine? in BPM? In the ESB?

When is it best to embed the rules code behind a sessionbean (maybe exposed as a WebService), called be the esb code? called by the bpm code? In a Rules container and centralized?

[kukeltje]

as i see it:

Rules (e.g. to decide which transition to take runtime) go into the rule engine. No overall process definitions

Workflow (human interaction) go into the BPM (JPDL!!, not BPEL) engine

ESB takes care of integration (file, ws, b2b messaging), service orchestration based on e.g. BPEL, transformation etc

[hanasakijiji]

Would anyone happen to have a specific example showing details? From a high level, it all makes sense. Devil is in the details :(

Thanks.

[kukeltje]

the jbpm examples contain a workflow/rules example. the esb comes in when e.g complex external services have to be called. an example of that has to de done by by yourself for the moment, but don't hasitate to post an example on the wiki.