UMLR — Simplify by Making UML More Consistent: Allow States to be model as classes supporting inheritance and composition

In OMT, states could be modeling on the class diagram, which was a powerful alternative approach to capture the structure of a state machine. It made clear the relationships between entry/exit actions of superstates on substates, the ability to override responses to trigger/actions pairs of superstates by a substate, the scope of a defer, what a history node really does, etc. understandable in a way that statemachines don’t do because of their different presentation style. This should also restore the ability to identify state-specific attributes and constraints, and the ability to specify parameters on the state’s possible behaviors – two features that have often been requested. Restoring this ability will make UML treatment of states more like their treatment for classes. Similar ideas have been periodically proposed, see http://www.conradbock.org/statemachine.html.