LAUSR

Decomposition and localization of a supervisor are both reduction methods in distributed supervisory control of discrete‐event systems. Decomposition is employed to reduce the number of events and localization is used to reduce the number of states of local controllers. In decomposition of a supervisor both observation and control scopes are restricted, whereas in localization only control authority is restricted to the corresponding local controller. In this paper, we propose a decomposition method by defining a coparanormality property, and by using the relative observability property of a monolithic supervisor. Coparanormality is a coobservation property defined based on a paranormality property for a set of natural projections. It is shown that each supervisor can be coparanormal, provided a set of appropriate natural projections exist. Moreover, it is proved that relative observability is a sufficient condition to decompose a supervisor. Furthermore, the supervisor localization procedure is generalized to find a set of local controllers for any partition of the controllable events set. The implementation of such local controllers may become easier in industrial systems.