The bottleneck was caused by a process performed at the machining center to finish internal bores after fine boring. The chief engineer of the production engineering team who was asked to propose and implement a plan to boost production recalls:
“Finishing of internal bores was performed at the machining center, taking an average of 120 minutes per set of workpieces. In the interests of accuracy, we machine multiple components as one in a stack, but the large number of bores made it necessary to reposition holders during machining. We were expending a significant amount of time on this task.”
Because final finishing was performed by a cutting process, wear on cutting heads caused inconsistencies in the bore diameters and surface roughness achieved after a given amount of cutting time. Any increase in production volume would made it necessary to replace cutting heads more frequently, each time stopping the production line and therefore creating significant downtime.
Deciding that speeding up the bore finishing process and ensuring consistent accuracy was key to improving productivity, the chief engineer discussed the matter with his team in the hopes of improving the process but struggled to find an effective solution.
