The Traffic Cop - Finding the Problem Tool Group

To identify the problem tool group, the traffic cop first looks at the bottleneck tool chart for the three shifts during which turns were high. Note that when looking over a relatively short period (36 hours), the utilization can exceed 100% for some tool groups. This is because utilization is based on maximum expected throughput, which includes assumptions about downtime. The first five tools in the figure below exceeded the expected throughput, at least for a short time. The 5xStep tool group runs at just below 100%.

Next, the Traffic Cop looks at the same chart, for the next three shifts (during the time period when moves and turns were down 15% or so). Here, the utilization of the 5xStep tool group is much lower, only 68%, and the 5xStep tool group appears to be nothing close to a bottleneck, a friendly green color on the chart. 

However, the Traffic Cop knows that over the week, the 5xStep tool group is expected to average a 90% loading. Operating at 68% for three shifts will cause a WIP bubble, and the price will be paid in later shifts. (Continue to the next page.)