Scheduling of Flexible-Sequenced Process Plans in a Mould Manufacturing Shop

Process planning and scheduling used to be two very separate processes. However, owing to the recognition of the intricate relationship between them, recent work has focused on integrating the two processes. The use of flexible process plans in scheduling allows more flexibility in production and thus gives substantial cost savings. It also increases the solution space of the optimisation problem and makes it more critical to have an effective optimisation algorithm than for traditional scheduling problems. This paper describes a process-planning and scheduling system that makes use of the branch and bound approach to optimise priority weighted earliness of jobs scheduled in a mould manufacturing shop. Instead of considering a flexible manufacturing system, this paper focuses on the demands of less integrated factories, which are especially typical of mould manufacturing shops. The layout of the system, the methodology of the algorithm and effectiveness of performance measures for real industrial use are discussed in the paper.