Multi-objective optimization of assembly lines with workers fatigue consideration

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 assembly line balancing problem with consideration of workers fatigue. We use ε-constraint approach to address both objectives and present the Pareto front. Experiments on instances from the literature are performed and discussed to highlight the trade-off between the numbers of workstations and fatigue.