Organizational Control of Discrete-Event Systems: A Hierarchical Multiworld Supervisor Design

An organizational control architecture for supervising a class of multilevel hierarchical discrete-event systems is proposed in this paper. The architecture can be built on the basis of a standard scalable hierarchical design method, formalizing a common design practice of structuring the control of a discrete-event organization bottom-up into a consistent multiworld control hierarchy. It is shown that, under some mild condition of fairness, a multilevel recursive control law exists that is optimal and nonblocking. This law governs the hierarchy top-down as a dynamic programming recursion, over which an organizational control algorithm is obtained that computes the control decisions partially online and in linear time. It is explained and illustrated how the approach reduces the complexity of off-line control synthesis and increases the online transparency of control operations.