The work-related musculoskeletal disorders (MSDs) occur when the worker's capabilities do not match the physical demands of work. In assembly lines, with the execution of repetitive tasks, workers are exposed to fatigue and ergonomics risks. Thus, there is a need to find compromises between assembly lines performance and physical demands and ergonomics. In this work, we introduce a general fatigue criterion for assessing workers fatigue. We propose a multi-objective mixed-integer linear programming model for the a…