The Optimal Number of Workers for Job Rotation to Prevent Workers from Occupational Hazards

Abstract

This paper focuses on the application of administrative control which utilizes the job rotation to prevent workers from occupational hazards at the workplace. In the unsafe workplace, workers in the job rotation program will be assigned to workstations with low or high occupational hazards so that 8-hour exposure to each hazard of all workers will not exceed the permissible exposure limits. When dealing with a high hazard level, the number of workers required for job rotation is possibly more than the number of workstations because some workers in some periods will be assigned to perform tasks in the safe areas. Therefore, this paper proposes the optimization approach to solve the mixed-integer programming models that try to minimize the number of workers used in job rotation under noise hazard and air contamination. The numerical experiments are provided to demonstrate the solution procedures. Finally, the effectiveness of the branch and cut search in an optimization software namely CPLEX is also discussed. Within the computational limit, CPLEX can determine the optimal solutions for small size problems and the feasible solutions for large size problems.