David Harel created a notation and formalism for hierarchial state machines that he called StateCharts. He defined a (fairly) complete StateChartSemantics as well as a StateChartNotation for representing them. Since that time (late 1980's) state charts have caught on in a major way. Both the notation and the semantics have been brought into UML, and there are a number of companies that provide state chart creation tools.
I became interested in state charts around 1992. At that time (and still) I was doing distributed factory automation applications. Though we had little inkling of it at the time, we were designing cooperating state machines and we had a hell of a time of it. We went at the problem in an ad hoc way, based on designing the messages that were exchanged between various applications. We used no tools of any kind, other than seriously flawed design diagrams for each application.
One of our difficulties was that it was very hard to capture (that is, design or visualize) anything more sophisticated than a simple SendReplyPattern?. As a result we frequently painted ourselves into corners and had to hack our way back out.
There had to be a better way: MyStateChartHistory.
I've thought a little about StateChartToolFeatures.
StateChartsTopics ...
D. Harel. Statecharts: A Visual Formalism for Complex Systems.
Science of Computer Programming, vol. 8, 1987.
D. Harel. On Visual Formalisms. Communications of the ACM, Vol. 31,
No. 5, pp. 514-531, May, 1988.
-- DaleBrayden - 06 Jul 2002
Current Rev: r1.1 - 03 Dec 2005 - 15:18 GMT - DaleBrayden, Revision History:Diffs | r1.1
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