For disjunct diagrams that is probabely an easy way. But if you for example want to show the interaction from Java-client through BusinessDelegate with ServiceLocator, SessionFacade, workflow SessionBeans, EntityBeans plus DAO to an external system, then I would like to see an example of where to cut the diagram into pieces and how to cut. There are no "black bullets" like in data flow diagrams or "Subsystem" in Package Diagrams. One good point to cut the diagram might be between a Business Delegate and a Session Facade. This might be true for class, component and interaction diagrams respectively. Another cutting line might be between Java-client and JSP/Servlet related classes. I even think that thinking in cuttable subsystems will prepare a well designed component diagram. For cutting between SessionBeans and Entity Beans I have no idea because there is not a single point that could be cut but a M:N relationship between SessionBeans and EntityBeans. For class, component and interaction diagrams UML as far as I know does not offer anything like it offers a "Subsystem" for Package Diagrams - am I right?. Any more ideas? Thomas.