Ronald, Do you mean the Business Process Management with JBoss jBPM book by Matt Cumberlidge? I've just finished reading it and it gives a very good overview on both BPM and jBPM with a good starter application. I would have liked to seen more developer oriented topics discussed in greater depth but given the stated audience of the book I guess that wasn't possible. In my scenario, I need to pass business-level exceptions back immediately after some validation (from the process to the UI layer) within the context of a conversation with a user; I'm using the process as a kind of orchestration mechanism. There are wait states later in the process but the validation step is the first. My initial thoughts were to create a generic exception similar to SQLException where I could set a code for each business level error and then wrap a collection of these in another exception which would be thrown by my stateless session bean wrapping the jBPM engine. Regards, Paul. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4080253#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...