Prognosis and recovery evaluation in flexible manufacturing systems supervision

This paper presents some solutions of decision-making aspects integrated in an approach of process failure monitoring suitable for complex systems like flexible manufacturing systems. A hierarchical and modular structure corresponding to the monitoring and control requirements is described. Each control and monitoring module is able to accept any signal from the lower levels of the hierarchy and must be able to elaborate an acceptable solution for each failure. When a failure is detected, the elaboration of a curative solution is furthered by the knowledge of the details of the current situation. The prognosis function has to foresee the consequences of the failure on the future operation of the system in order to give relevant data to the decision function. Recovery evaluation is necessary to foresee what will be the consequences of the introduction of a corrective sequence on the current schedule.