ERGONOMIC ASSEMBLY LINE BALANCING

Tasks are distributed among workstations as smooth as possible in accordance with the precedence relations in assembly line balancing. However, just smoothening the total station time between stations can be meaningless in many industrial circumstances. In other words, two stations whose total station times are equal may contain tasks with different ergonomic loads. Consequently, their degrees of strain can be very different. This situation is underestimated in classical assembly line balancing, but it is an important aspect in reality. Especially in manual assembly lines, same type of work is done by the operator repetitively. As a result, there is a cumulative effect of repetitive work on worker. Assembly lines which are not well-designed ergonomically, cause not only lack of productivity, but also occupational diseases of workers. In order to prevent these complications, the acceptable risk level for a station should be analyzed and ergonomic risk factors of the station must be below this highest acceptable level. OCRA index, which is a very efficient procedure for ergonomic risk assessment, is explored in this study. The parameters of the method are explained in detail, and a comparison between ergonomically designed and non-ergonomic assembly line and is presented