Modelling multi-stage manufacturing systems for efficient scheduling

A novel approach to modelling complex, multi-stage manufacturing systems is presented. This approach is both generally applicable and powerful. The purpose of the model is to underpin the development of short-term schedules for the large variety of manufacturing systems present in the process industry. Such systems comprise stages that consist of parallel units and are dedicated to specific tasks such as producing, packing or intermediate storage. A two-level model is developed. At the first level, a generic model enables the formal definition of different systems. The second level deals with the system operations, providing a heuristic algorithm for the scheduling of individual processes. Based on the model, a solution representation is developed by dividing demand into sublots and treating each sublot sequence as a system schedule. Metaheuristic search is employed for the identification of efficient sequences. The results of a case study on a real-life industrial plant are presented.