I've been thinking a little more about this and it indeed contains generic requirements. I have one question though. In your original post you say anonymous wrote : So e.g. Observer1 can only continue after it gets a signal from both Item1 and Item2. What is 'continue' here? Is the subprocess in a certain state and can continue from there? Is the subprocess not even started? When you give me these details, I think we can work out a nice solution. Using events is indeed an option where you combine my state/decision 'block' into an eventhandler on a state (that is what I got from re-reading your initial post) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4176322#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...