Modeling Complex Behavior Simply Or How Much Is Too Much?

Recently, hierarchical state models such as Hare1 statecharts have been vigorously promoted over flat (Mealy-Moore) state models as a panacea for complexity management. Unfortunately, hierarchical state models have a number of severe shortcomings: complex, difficult to learn notation; too many ways of saying the same thing; ill-defined semantics; layers of content-free hierarchy adding to and hiding system complexity; and so on.