Clustering methods for production planning and scheduling in a flexible manufacturing system

This paper addresses the issue of tool management in a FMS composed of two machining centers. Machines are equipped with local tool magazines and a tool handling system is in charge of tool movements between the tool room and the two machines. Each machine is able to perform any operation, provided it is equipped with the suitable tool. Depending upon the schedule conflicts on the tool usage may occur. The overall problem is to assign parts to machines, sequence them on each one and synchronize tool movements through the cell. The proposed heuristic is based on two main blocks: a clustering procedure aimed at identifying parts with similar tools requirements, and a sequencing procedure which tries to avoid conflicts on tool usage.