OPTIMAL PRODUCTION AND MAINTENANCE PLANNING FOR FLEXIBLE MANUFACTURING SYSTEMS

In this paper, we establish a theoretical framework for a class of production and maintenance planning problems. The results obtained in this paper include the local Lipschitz property of the optimal cost function, the existence of optimal control policies, also necessary and sufficient conditions for optimality. The maintenance considered involves activities such as lubrication, routine adjustments, etc. The effect of the maintenance is modeled as the control constraints. By using the concept of viscosity solutions, we can relax some restrictive smooth assumptions on the optimal cost functions.