First impressions: 1. In PVM the process instance and the top level execution were recognized as being the same thing, sans a few extra properties in the process instance. The aggregation of nested executions should be in the Execution itself, while ProcessInstance should extend Execution. 2. Given the above consideration, ExecutionManager and ProcessInstanceManager should be merged. 3. Is "attachment" a synonym of [process] variable? If so, I believe the latter term should be used. Otherwise, can you clarify the concept and whether it maps to an existing class in jBPM 3? 4. The transition router usage model is not clear to me. I guess you are still working on it, tough. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4162619#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...