Thanks a lot. You basically anwsered my question. I reviewed the bpm_orchestration3 sample included in jbossesb-server-4.2.1GA\samples\quickstarts. This sample is just one process that has 3 nodes, but its design is similar to what you described. What I really need to confirm is: Is it possible that without any other external actionhadler or MDB, only processA and processB, can they achieve this effect? I mean, can the nodes alone in the BPM process definition achieve the function of posting message or being invoked by message? Thanks again! View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4147904#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...