SPC Control Charts & Analysis

Question 1

What is the purpose of the center line on a control chart?

Accepted Answer

Process mean

Answer

Upper specification limit

Answer

Process target

Answer

Median of all samples

Question 2

What does it indicate when points trend steadily upward on a control chart?

Accepted Answer

Possible process shift

Answer

Improved efficiency

Answer

Stable process

Answer

Random variation

Question 3

Which type of control chart is best for monitoring process variability?

Accepted Answer

R-chart

Answer

P-chart

Answer

X-bar chart

Answer

Histogram

Question 4

How many standard deviations from the mean are typical control limits set at?

Accepted Answer

3

Answer

1

Answer

2

Answer

4

Question 5

Which of the following may indicate a process is out of control?

Accepted Answer

One point outside control limits

Answer

All points near the center line

Answer

Even distribution of points

Answer

Stable control limits

Question 6

What is the main difference between control limits and specification limits?

Accepted Answer

Control limits are process-based

Answer

Control limits are wider

Answer

Specification limits are based on samples

Answer

Specification limits change over time