ABSTRACT
A growing requirement inmanufacturing is guaranteed and quantified quality, as measured, for example, by the proportion of a product lying outside some prespecified limit. In continuous processes, such as papermaking, it is important that the output (at worst) exceeds some lower quality limit (e.g., thickness of paper). To ensure that this is so, the average thickness must be set greater than the minimum by an amount dependent on the variance of the controlled output. Hence, if this variance is minimized, the manufacturer can reduce the average, as shown in Figure 33.8.
