The problem of assigning rest times to reduce physical ergonomic risk at assembly lines

Line balancing and job rotation have been recently found to be effective methods to reduce workers' ergonomic risks since the design/planning phase of assembly lines, and at the same time to limit performances deterioration and/or costs increments. As far as we know, there are no papers in the literature that deals with the problem of assigning rest times to workers in assembly lines with the aim to reduce their ergonomic workload. In the paper the problem of assigning rest times to workers in assembly lines is considered (Rest Time Assignment Problem). We show how rest times assignment affects ergonomic risk of workers in mixed-model assembly lines when this is evaluated through the Occupational Repetitive Action index (OCRA), and suggest and approach to simultaneously find solutions for the Assembly Line Balancing Problem and the Rest Time Assignment Problem. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.