A sheet-metal bending operation produces bent parts with an included angle = 92.1°. The process is in statistical control and the values of included angle are normally distributed with a standard deviation = 0.23°. The design specification on the angle = 90 ± 2°.
(a) Determine the process capability.
(b) If the process could be adjusted so that its mean = 90.0°, determine the value of the process capability index.