I think statecharts are even more useful than sequence diagrams in documenting behaviour. Statecharts are Turing complete, and succinctly visually encode comple

I think statecharts are even more useful than sequence diagrams in documenting behaviour. Statecharts are Turing complete, and succinctly visually encode complex behaviour that is going to take reams of text to describe. Harel et al have done serious, rigourous work in developing statechart.