Scheduling algorithms for job-shop-type remanufacturing systems with component matching requirement

Abstract

This study considers a scheduling problem for remanufacturing systems with parallel disassembly workstations, a job-shop-type reprocessing shop and parallel reassembly workstations, where the components obtained by disassembling a product must be matched when reassembling the corresponding remanufactured product, i.e. component matching requirement. The problem is to determine the allocation/sequence of jobs on the parallel disassembly workstations, the sequence of the jobs on each workstation of job-shop-type reprocessing shop and the allocation/sequence on the parallel reassembly workstations. To represent the matching requirement, the reprocessing jobs are grouped into job families each of which corresponds to a product to be remanufactured. After an integer programming model is developed, two types of solution algorithms, decomposed and integrated ones, are proposed, where the decomposed ones solve the disassembly, reprocessing and reassembly scheduling sub-problems separately while the integrated ones solve them at the same time after representing the problem as an extended disjunctive graph. Computational experiments were done on a number of test instances and the results show that the integrated algorithms outperform the intuitive decomposed ones significantly.