A Model to Enhance the Effectiveness of Machining Centers with Automatic Multi-Pallet Changers: a Case Study

Sammanfattning: The purpose of this thesis is to develop a model to enhance the effectiveness of machining centers with multi-pallet automatic pallet changers (APCs). From critical literature review no existing theories within this field were found. The multi-pallet APC allows multi-setups and a more flexible sequencing of jobs. The model together with the developed heuristic scheduling algorithm with the objective to minimize the total weighted tardiness can be used to plan in n jobs on m pallets in a shop-floor. The right maintenance policy ensures a high availability, which together with the program guarantees a high level of utilization of the machinery. Consequently the effectiveness will be enhanced. A case study approach was used to test the model at Växjöfabriken in Sweden, which treats cast material. The results of this case study are a more effective utilization of the machines with decreased tardiness costs, increased customers’ satisfaction and goodwill of the company. The contribution of this thesis is a model with a flexible, adjustable and expandable heuristic scheduling algorithm, which can be applied in all manufacturing companies using machining centers with multi-pallet APCs.