Special cause (nonrandom)variation in a process is more likely to be detected with
A)wider control limits
B)narrow control limits
C)wider specification limits
D)narrow specification limits

Question

Quizplus · Accepted Answer

Narrow control limits increase the sensitivity of the control chart to detect special cause variation, as it reduces the natural variability in the process and makes any nonrandom pattern more visible. Wider control limits increase the chances of Type II error, where a special cause variation goes undetected due to the chart being insensitive. Specification limits are unrelated to the detection of special cause variation as they describe the acceptable range for the final product, not the process variability.

Special Cause (Nonrandom)variation in a Process Is More Likely to Be