Including ergonomics aspects into mixed-model assembly line balancing problem

Not considering ergonomics in the assembly systems can bring to sub-optimal solutions and, in case of high levels of ergonomics risk in the tasks execution, several musculoskeletal disorders affecting the global performance of the assembly line. Several papers have been developed in the last years about how to integrate the ergonomics aspects into traditional Single Assembly Line Balancing Problems (SALBP). In this paper, we have extended our recent integrated ergonomics approach to the Mixed-model ALBP (MALBP), where many products are processed in the assembly system in the same period. First, a theoretical model has been developed in order to simplify the MALBP into SALBP, under time and ergonomic approaches. Then the behavior of the assembly system with the real products has been evaluated in terms of time smoothness and ergonomics levels. General discussions and future agenda will be introduced at the end of the paper.