Enhancing Ergonomics in Assembly Lines by a Genetic Approach

Ergonomics represents nowadays a key feature to be considered while designing manual assembly lines, as it may affect both productivity and human factor issues. Repetitive movements and handling of high weight components are frequent during assembly processes and may result in operator’s overload. To enhance ergonomics on manual stations, assembly tasks should be distributed on the line so as to smooth the workload among the different workers, based on their physiological limits given by individual characteristics. The aim of this work is to present and validate a software tool that uses a genetic algorithm for solving a multi-objective version of the assembly line balancing problem, in which one of the objective is the optimization of ergonomic aspects. In the developed system, the assignment of workers available in a company to the stations of an assembly line considers physical capabilities and limits of workers, from an energy expenditure point of view. The other objectives of the problem are the minimization of the number of stations and the distribution of assembly tasks to stations according to worker technical skills. To demonstrate the efficacy of the system, tests for different case studies are presented and discussed.