Presents the modelling and supervisory control design of a subway system. This transport system consists of several tracks connecting various stations and junctions. Each train has a departure point and a destination. Its route need not be fixed but it cannot change direction. The authors propose a design technique to model the system using finitely recursive processes. The model is described using extended processes which include the logical branching and the assignment operators. The system is modelled in a top down way using an interactive graphical representation of both structure and behaviour based on systems decomposition, subsystem interaction and subsystem behaviour. The model is constructed using the system's hierarchical structure and the connections between inputs and outputs of its subsystems. Next the authors address the problem to develop control strategies in order to ensure desirable behaviour of the model. Instead of attempting to construct the complete control policy for the discrete event system, the authors propose a distributive control system where each component of the system is controlled by a "local" controller following ("dynamic") global specifications. Such a local controller can perform "dynamic" control in the sense that it disables and enables events depending on the ("dynamic") process behaviour. This technique is appropriate for complex discrete event systems or for "dynamic" plants, and desired behaviour where no automaton representation is available.<<ETX>>