Extending the ExpressionAssignmentHandler is indeed one thing to implement. Replacing the existing one is another. The reason it was probably not answered may have to do that if the source is used (a very good source of information), you will see a limited number of references and a conclusion could be very easy to draw: Currently, from what I FOUND, it is not configurable, at least not without adapting the source. The file org.jbpm.jpdl.xml.JpdlXmlReader contains a fixed reference to the default ExpressionAssignmentHandler : assignmentDelegation.setClassName("org.jbpm.identity.assignment.ExpressionAssignmentHandler"); so it could be that changing this, recompiling the code and running it, solves it. Give it a go.... View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3961136#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...