The car sequencing problem is a widespread short-term decision problem, in whichsequences of different car models launched down a mixed-model assembly line are tobe determined. To avoid work overloads of workforce, car sequencing restricts themaximum occurrence of labor-intensive options, e.g., a sunroof, in a subsequence ofa certain length by applying sequencing rules. Existing research invariably assumesthat the model sequence can be planned with all degrees of freedom. However, inreal-world, the sequence of cars in each department can not be arbitrarily changedbut depends on the sequence in previous departments and disturbances like machinebreakdowns, rush orders, or material shortages. Therefore, in reality the sequencingproblem often turns into a resequencing problem. Here, a given model sequence hasto be reshuffled with the help of resequencing buffers (denoted as pull-off tables).This paper formulates the car resequencing problem, where pull-off tables can beused to reshuffle a given initial sequence and rule violations are minimized. Theproblem is formalized and problem-specific exact and heuristic solution proceduresare developed and studied. To speed up search, a lower bound as well as a dominancerule are introduced which both reduce the running time of the solution procedures.Finally, a real-world case study is presented. In comparison to the currently usedreal-world scheduling approach, the resequencing approach can improve solutionquality by on average about 30%.[...]
