MULTI-OBJECTIVE ERGONOMIC WORKFORCE SCHEDULING UNDER COMPLEX WORKER AND TASK CONSTRAINTS

When workers are assigned to perform a set of tasks with exposure to some safety/ergonomics hazard, they can be rotated among those tasks periodically within a workday so that their daily hazard exposures do not exceed a permissible exposure limit. Assigning the right workers to the right tasks in each period can help to increase the work system productivity. It is necessary to consider worker limitations and job requirements when developing an optimal set of work schedules for all workers. A multi-objective ergonomic workforce scheduling problem (MO-WSP), with combined cost and productivity considerations, is described. Three problem objectives are considered: 1) minimizing the number of utilized workers, 2) maximizing the total worker-task fit score, and 3) minimizing the total worker-task changeover. A preemptive optimization approach and a heuristic procedure are employed to generate safe daily rotating work schedules for workers.