A study of the utilization of capacity constrained in drum–buffer–rope systems

Goldratt, the originator of the Theory of Constraints, maintains that only the system's primary resource constraint(s) should be scheduled at 100% of capacity. All other resources should have excess capacity. This paper presents the results of a simulation experiment that studies how changes in the capacity utilization of a system's two most heavily utilized resources affect the performance of a drum–buffer–rope scheduling system. The research demonstrates that 100% utilization of the primary constraint is not optimal. It also shows that DBR responds well to relatively low levels of increased capacity at the operation's second most heavily utilized resource. This research also highlights several other issues related to capacity utilization that need further investigation.