A GENERAL CONTROL FRAMEWORK FOR MANUFACTURING SYSTEMS

A general hierarchical control framework is considered in order to support the integrated planning and scheduling of manufacturing systems. These may be viewed as complex discrete event dynamical systems whose state evolution, governed by several decision layers, occurs in different time scales and is affected by both undesirable perturbations as well as by relevant interactions with other independent external systems with which it shares segments of the supply chain. Motivated by the analysis of two different classes of production systems having in mind the respective integrated planning and scheduling, this approach is supported in a properly adapted Systems Engineering Process in order to capture all the relevant ingredients underlying the decision-making at all levels of the hierarchy. It is recognized the role of the optimal control framework at the coordination level as well as in providing the interface to the supply chain integration level. While in the first one, complexity and random factors are dealt with by embedding the basic problem into a receding horizon scheme, in the second level, a Hybrid Systems framework plays a fundamental role in enlarging the scope of decision-making which now encompasses system's reconfigurability.