Product scheduling and manufacturing line reconfiguration using Petri Nets and heuristic search

The manufacturing industry is experiencing a major change from mass production to mass customization. Both dedicated machine line (DMLs) and flexible manufacturing systems (FMSs) fail to deal with the new market characteristics in a cost-effective manner. One alternative is reconfigurable manufacturing systems (RMSs) that can provide a high degree of capacity scalability and functional adaptability through different configurations. The reconfiguration ability of RMSs, however, leads to great challenges over product scheduling. On the one hand, the product scheduling should take into consideration possible configurations; on the other hand, the configuration should meet the needs of scheduling. These two issues are closely related and have a strong impact on each other. Therefore, the product scheduling and configuration should be concurrently addressed to obtain the optimal or near-optimal solutions. In the paper, firstly, an integrated model based on deterministic timed Petri nets (DTPN) is developed to deal with the two problems simultaneously; secondly, the heuristic search algorithm is proposed to obtain the optimal or near-optimal solutions; lastly, an example of aerospace automobile electromechanical manufacturing line is presented to verify the efficiency and effectivity of the proposed model and algorithm.