Mathematical formulations for scheduling in manufacturing cells with limited capacity buffers

In the past decade, the deadlock-free scheduling problem in flexible manufacturing systems has received much attention from researchers and practitioners. This is due to the growing trend of automation, and the rising need for flexible manufacturing systems that can cope with the everyday changing market demand. In this article, mixed-integer programming formulations for the deadlock-free scheduling problem of flexible manufacturing cells are proposed. A job shop environment is assumed where each job may have a different processing route. The proposed models consider the presence of different types of buffers in the system. Furthermore, to enhance the comprehensiveness of the models, a heuristic to insert transportation operations into the obtained schedules is proposed. Finally, computational experiments are conducted to investigate the performance of the proposed models in terms of efficiency and computational time.