Minimizing makespan for multi-spindle head machines with a mobile table
Résumé
This paper presents a novel application of operational research techniques in Manufacturing. This concerns scheduling of multi-spindle head machines with a mobile table to minimize the makespan. We show that this problem can be formulated as scheduling for a single max-batch processing machine with inclusion, exclusion and precedence constraints between jobs. What makes this study unique from others in literature is that the batch processing time can exceed that of the longest job in the batch. The job compatibility and the batch time depend on the batch content, i.e. which jobs constitute the batch. This problem is transformed into finding the constrained shortest path in a specially constructed digraph. Dominance properties are developed to decrease the digraph's size. An industrial example is presented to illustrate the effectiveness of the proposed techniques.