Constraint-based Scheduling for Closed-loop Production Control in RMSs

Reconfigurable manufacturing systems (RMS) are conceived to operate in dynamic production contexts often characterized by fluctuations in demand, discovery or invention of new technologies, changes in part geometry, variances in raw material requirements. With specific focus on the RMS production aspects, the scheduling problem implies the capability of developing plans that can be easily and efficiently adjusted and regenerated once a production or system change occurs. The authors present a constraint-based online scheduling controller for RMS whose main advantage is its capability of dynamically interpreting and adapting to production anomalies or system misbehavior by regenerating on-line a new schedule. The performance of the controller has been tested by running a set of closed-loop experiments based on a real-world industrial case study. Results demonstrate that automatically synthesizing plans and recovery actions positively contribute to ensure a higher production rate.