Central Limit Theorem -- Dickeson

Why is this significant for our industry? We simply have to get a better grip on managing variation. Right now, it manages us.

W. Edwards Deming taught us: Reduce variance to manage productivity and quality. In the chart the difference between the upper and lower control limits—the range—is 8,700 impressions per hour. Great golly, Molly! To predict with 99.7 percent validity, the best we can say is that this press will produce a job at a net speed somewhere between 20 and 29,000 iph. If you're satisfied with 95 percent predictive accuracy you can narrow the range to 5,800 iph. Cut to 68 percent accuracy and you're within 2,900 iph.