The impact of simultaneous continuous improvement in setup time and repair time on manufacturing cycle times under uncertain conditions

Abstract

We develop a system dynamics model to examine the cumulative effects of continuous improvement programmes for repair and setup times on the cycle time of a simple single-stage production system. The relationship between system performance and repair and setup times is captured using the Factory Physics approach. We find that modest rates of improvement in multiple areas in parallel yield cumulative benefits over time comparable with those obtained by a large reduction in a single parameter, especially when there is significant uncertainty in the degree of improvement that can be obtained, or in the degree to which improvements can be sustained over time. These results provide an insight into the success of the Toyota Production System and related lean manufacturing approaches where continuous improvement is an ongoing activity across the work environment.