Modelling job rotation in manufacturing systems with aged workers

The increasing trend of retirement age in Europe represents a critical phenomenon for manufacturing and material handling activities, where repetitive activities, involving the handling of different loads at various frequencies, are usually required. These tasks can lead to occupational diseases and work-related musculoskeletal disorders, which can affect more heavily older workers, due to their decreased functional and physical capacities. On the other side, older workers positively contribute to the manufacturing processes through their expertise and their skills developed over time. This paper introduces a bi-objective mathematical model useful to assign different workers exposed to the risk of repetitive work to various workstations. A person-job fit approach is proposed, which analyses the workers’ physical capacities, competencies and mental and relational skills together with the requirements of each workstation in terms of capabilities and ergonomic load. The aim is to define the activities scheduling through two objectives: the first one considering the matches among workers abilities and workstations activities, the second one reducing the ergonomic risk of repetitive work by varying the assignments during the work shift. The method is also applied to an industrial case, whose results show its applicability and potential benefits, in terms of ergonomics and overall efficiency improvement.