Integrated optimization of production planning and scheduling for flexible jobshop

Abstract

The production planning and scheduling of flexible jobshop is more difficult than Jobshop for its multiple selection of processing route and multiple equipments for single process. In the traditional serial production planning and scheduling in flexible jobshop, the plan cannot respond to the changes in scheduling and the changes cannot be feedback in time. So the integrated optimization complete model of production planning and scheduling for flexible jobshop based on multiple objectives and constraints was constructed. For the difficulty in solving the integrated optimization complete model, an improved discrete particle swarm optimization (IDPSO) was presented to solve the model in discrete space. The segmented encoding method suited for discrete code was proposed to avoid the unfeasible solution and improve the efficiency. A dynamic parameter methods and self-adaptive escapes and variation scheme were proposed to enhance the diversity of particles. For the production planning and scheduling of a metal processing shop on 5 products in 4 cycles, the experiments validate the presented model and algorithm can realize the simultaneously optimization of production planning and scheduling in flexible jobshop and contribute to the performance improvement and the application scope extension of the particle swarm optimization algorithm. © 2012 Praise Worthy Prize S.r.l.