Zhang, ZikaiTang, QiuHuaRuiz García, RubénZhang, Liping2021-04-292021-04-292020-060305-0548https://riunet.upv.es/handle/10251/165755[EN] Workers still perform the bulk of operations in the manufacturing industry. The consideration of the assignment of workers and the reduction of ergonomic risks in U-shaped assembly lines is of paramount importance. However, the objectives of efficient task and worker assignment and a reduction in ergonomic risks are not usually correlated. Moreover, there is limited research in the existing literature into multi-objective approaches in U-shaped assembly lines. We formulate a U-shaped assembly worker assignment and balancing problem to simultaneously minimize cycle times and ergonomic risks. In addition, and due to its simplicity and successful results in flow shop scheduling problems, a Restarted Iterated Pareto Greedy algorithm is designed to optimize both objectives. In this algorithm, a problem-specific heuristic-based initialization is extended to improve the initial solution. Two precedence-based greedy and local search phases are developed to exploit the space around the current solution. Finally, a restart mechanism is proposed to help the algorithm escape from local optima. Comprehensive computational results, supported by detailed statistical analyses, suggest that the proposed multi-objective algorithm outperforms existing methods on a large number of benchmark instances.Reconocimiento - No comercial - Sin obra derivada (by-nc-nd)U-shaped assembly lineWorker assignmentErgonomic risksMulti-objectivesESTADISTICA E INVESTIGACION OPERATIVAArtículo10.1016/j.cor.2020.104905Abierto