In the field of supervisory control of discrete event systems (DESs), finite‐state automata (FSA) are universally used to represent the system's behavior. A DES is a system whose behavior is not controlled by the time but by the occurrences of events. A finite‐state automaton is a graphical representation of a language. In a DES, the alphabet of the language is the set of all the possible events characterizing the system, and then the language is the set of all the possible event sequences in the system. The structure function of the system consequently becomes an automaton language. This is the first dynamic aspect of the system's structure function. The functional model is a set of integro‐differential equation systems whose inputs derive from a deterministic and/or random generator. Each integro‐differential equation system is associated with a subset of states of the FSA.