To see the effect of reducing the standard deviation of the piston radius:
Enter this same value in the Upper Limit cell, I18.
Now, the table of flow rate variables is displayed as shown in Figure 179, Flow Rate Variable Initial Values and Limits.
Reset and run the simulation again.
The Flow Rate Forecast chart is displayed, similar to Figure 180, Flow Rate Forecast Chart After Model Adjustment.
In Figure 180, Flow Rate Forecast Chart After Model Adjustment, quality appears much better than that shown in Figure 166, The Cycle Time Forecast with Process Capability Metrics. The mean is less than 1.5 standard deviations lower than the target, and the standard deviation is smaller. USL is almost 6 sigmas away from the mean (Z-USL = 5.68) and LSL is over 2 sigmas away (Z-LSL = 2.49). The certainty of the forecasted flow rate falling within LSL and USL is now over 99%.
The Total Cost Forecast chart has also changed, as shown in Figure 181, The Total Cost Forecast Chart after Model Adjustment. The quality improvements result in higher costs. Where the total cost per pump was $26.73, now it is $33.47, a 25% increase. You and the team must determine whether to sacrifice quality to lower the cost or whether to test modifications to the other three flow rate variable components as well.
