Multi-Workday Ergonomic Workforce Scheduling With Days Off

Abstract

Most ergonomic workforce scheduling problems (WSPs) are concerned with developing daily work schedules for industrial workers so as to prevent their daily hazard exposures from exceeding a permissible limit. In this paper, we consider the WSP with a planning period that covers several workdays. Additionally, allowable days off are included in the work schedules. It is assumed that all workers working at the same workstation (or in the same work area) are exposed to the same hazard level. Daily operation schedules of workstation and worker limitations are also considered. An integer linear programming model is developed to represent the multi-workday ergonomic workforce scheduling problem. Its objective is to determine a minimum number of utilized workers for the given planning period such that all workers' daily hazard exposures do not exceed the permissible daily limit. An optimization software tool called ILOG CPLEX is employed to obtain the optimal solution.