Question & Answer: Up to this point, we have considered how the weights of the clients vary (statistically)…..

Up to this point, we have considered how the weights of the clients vary (statistically) but have not considered the needed weight of the overshoes. Moreover, as the weight of the clients vary, our ability to consistently make overshoes has variability. That is, the processes in our factory cannot make every overshoe the same weight. Furthermore, we do not want to make the overshoes any heavier than necessary as it costs us extra money without creating any more value for the customer. Our goal is to analyze how consistently our process makes overshoes and then make sure that we never make product that fails to sink a client. On the accompanying Excel spreadsheet, I have provided data on the performance of our manufacturing process over time (with regard to overshoes weight). To provide extra assurance that the mean of our process will not drift from its desired value, assume that we want the lower specification (not SPC) limit to be 4 standard deviations from our manufacturing process mean.