Workload Control (WLC) seeks to align capacity with demand, where capacity is typically assumed to be restricted by a single constraint – machine capacity. In practice however, shops are often restricted by dual resource constraints: labor and machines. This study therefore uses simulation to investigate the performance of WLC in Dual Resource Constrained (DRC) highvariety
shops with fully interchangeable labor. By considering several environmental factors and different labor assignment and dispatching rules, it is demonstrated that the order release function of WLC maintains its positive impact on performance in a DRC shop under different staffing levels. The positive effect of considering labor availability at release, as proposed in previous research, could not however be confirmed. Thus, the original release method can be applied if
labor is fully interchangeable. In terms of labor assignment, we show that a distinct assignment pattern that differs between upstream and downstream stations improves performance if the routing is directed. Meanwhile, dispatching plays a less important role but creates important interaction effects with the assignment rule. Finally, the results suggest that increasing the service
rate is a better response to the reduction in capacity that results from labor absenteeism than lowering the input frequency of work