ProcGraph: a procedure-oriented graphical notation for process-control software specification

This paper presents a procedure-centric approach to process-control software specification. A high-level, domain-specific specification notation called ProcGraph was developed, based on three types of diagrams that describe the modelled system using a domain-oriented hierarchical structure of interdependent procedural control entities and state-transition diagrams. The state-transition diagrams describe the behaviour of the procedural control entities. The processing content of the states is defined by sequential programs. In order to illustrate the presented models and notation, some segments of a real process-control application that deals with the drying process in the production of titanium dioxide are presented.