Priority scheduling to minimize the total tardiness for remanufacturing systems with flow-shop-type reprocessing lines

This study considers the scheduling problem in remanufacturing systems in which end-of-use/life products are separated into their components at a single disassembly workstation, then each component is reprocessed at one of parallel flow-shop-type reprocessing lines, and finally the reprocessed components are reassembled into remanufactured products at parallel reassembly workstations. The problem is to determine the sequence of products to be disassembled at the disassembly workstation, the sequence of components to be reprocessed at each workstation of the reprocessing lines, and the allocation and sequence of the products to be reassembled at each reassembly workstation for a due date-based objective of minimizing the total tardiness. A mathematical programming model is developed to represent the problem, and a priority scheduling approach is proposed for practical applications. To test performances of priority rules, simulation experiments were done on various test instances, and the results are reported. In particular, we show from additional tests that the approach proposed in this study outperforms the previous one that determines reprocessing and reassembly schedules according to the sequence of disassembling products significantly, and also, the rule combination approach that uses different priority rules on disassembly, reprocessing, and reassembly shops outperforms the single rule approach that uses the same rule over the three subsystems.