In: IEEE Transactions on Software Engineering, Vol. 19, No. 2, pages 165-180. 1993.
Abstract: A graphic-based language known as extended systems modeling language (ESML), which is an extension of the data flow diagram notation for representing control logic in models of real-time systems, is analysed and summarized aiming at a rigorous interpretation of ESML symbols and their combinations. Based on elementary and compact (''high-level'') Petri nets (PN), to which a succint introduction is given, formal foundations for ESML, in particular for its transformation schema (TS) notation, are proposed. Translation principles as well as examples of usual transformation and flow patterns are presented both in TS notation and in PN notation. The resulting PN models are rigorous and accurate models of the dynamics of real-time systems with signals, prompts and data flows of various kinds.
Keywords: extended systems modelling language; data flow diagram notation; control logic; transforamtion schema; high-level net.