DOI: 10.1016/j.ergon.2017.05.011">

Effect of cycle to cycle task variations in mixed-model assembly lines on workers’ upper body and lower back exertions and recovery time: A simulated assembly study

Document Type


Publication Date



Engineering Technology

Publication Title

International Journal of Industrial Economics


Differences in cycle-to-cycle work content in mixed-model assembly lines (MMAL) may increase exposure to risk factors of work-related musculoskeletal disorders (WMSD). This study investigated the effect of conveyor type and product mix/sequence in MMALs on joint loads and recovery time. An assembly task was simulated using 9 conveyor (continuous moving, synchronous indexing, and asynchronous indexing) and product mix/sequence (single product, 3 products with fixed sequence, and 3 products with random sequence) configurations. Results show the self-paced conveyor resulted in the least frequency of reaching. However, subjects did not use the available time for recovery and worked at a faster pace than in the continuous and synchronous indexing conveyors. In conclusion, an asynchronous indexing conveyor provided workers the flexibility they needed to complete their job correctly without reaching but recovery time was not sufficient.

Link to Published Version

DOI: 10.1016/j.ergon.2017.05.011