9.9 In March 1990, some math instructors and cadets visited Microtome Precision Inc. of Colorado Spring to help them improve their process capability for manufacturing a precision Delrin ring used on high speed disk drives. The specifications for the outer diameter of this ring are 1.557 ± 0.001 inches, which is a critical dimension. A capability analysis of the process before improvement techniques were implemented yielded the following statistics from 86 runs : (Assume that the outer diameter is normally distributed.)