AN EFFICIENT HEURISTIC APPROACH TO RECOGNIZE THE INFEASIBILITY OF A LOADING PROBLEM

The success of hierarchical production planning approaches for flexibl e manufacturing systems lies in the consistency of decision outcomes a t various decision levels. For instance, the loading problem, which is solved at a lower level, may not yield a feasible loading solution to a set of part types selected at a higher level. This paper attempts t o address the issue of recognizing the infeasibility of a loading solu tion. We present a modified loading model that includes a penalty for each operation not assigned to any machine. We develop a Lagrangian-ba sed heuristic procedure and provide a sufficient condition on the qual ity of heuristic solutions that, if satisfied, will enable us to use t he heuristic solutions to recognize the infeasibility of a loading pro blem. The proposed model and the dual-based heuristic can be effective ly incorporated in an FMS hierarchical production planning approach th at finds a good loading solution by iteratively comparing different pa rt grouping scenarios.