Models Arising from a Flexible Manufacturing Machine, Part II: Minimization of the Number of Switching Instants

This paper deals with a job scheduling problem for a flexible manufacturing machine. We consider the same manufacturing environment described in a companion study (Part I), but we use a different performance criterion: to minimize the total number of instants at which tools are switched. This performance criterion is appropriate when the switching time is roughly constant and independent of the number of tool switches. We show that this scheduling problem generalizes the classical bin packing problem, and we present a non-LP-based branch-and-bound procedure that terminates with an optimal solution. We extend this procedure to the case of K machines in sequence.