But in JBPM3 even if there is a chnage in the class definition one need not version their classes. JBPM takes care of the class versioning itself. But it seems that facility is not there in the JBPM4 please refer <JBPM4 Home directory>/doc/userguide/html_single/index.html#deployingclasses. But once discussing with one of the guy somewhere I came to know there is a way to handle this without changing the class but I could not recollect it. So posted in the forum. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4245723#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...