The point is, that metadata that apply may Executions should be externalized a separate document. In J2EE you find this in the various deployment descriptors. The implementation i.e. the Servlet or EJB is seperated from that metadata. anonymous wrote : I put process variables on the instance Binds your implementation to the processing of this metadata. Every client of the API would have to invent its own meta data processing if this is not generalized at Engine level. Lets defer this discussion until I can show you a proposal in code. This is when http://jira.jboss.org/jira/browse/JBPM-1325 is done. You can then take that proposal and comment/improve on it. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4162864#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...