An environment for specifying and executing hierarchical Petri nets

An environment for the construction and execution of requirement specifications for embedded systems is described. High-order Petri nets are used as a notation for the specifications. The environment consists of a net browser, a net editor, an animated net simulator, and a simulation engine. A hierarchically structured specification can be constructed using the graphics-based net editor. The animated simulator helps to detect errors and inconsistencies. The net browser enables management of several net hierarchies and the retrieval and reuse of nets. The simulation engine allows specifications to be executed in real time in the real environment. The authors concentrate on the net browser and the concepts, methods, and graphical notations used for improving the usability of high-order Petri nets