Statistical Process Control (SPC) Quiz

What is the primary purpose of Statistical Process Control (SPC)?

• To monitor, control, and improve processes by analyzing performance data

• To eliminate all variations in a process

• To increase production speed

• To reduce the number of employees

Who is credited with the development of the control chart?

• W. Edwards Deming

• Joseph Juran

• Walter Shewhart

• Kaoru Ishikawa

What is a control chart used for in SPC?

• To train employees

• To plot process data over time and distinguish between common and special cause variations

• To calculate the cost of production

• To design new products

What is the difference between common cause and special cause variation?

• Both are due to external factors

• Both are inherent in the process

• Common cause variation is inherent, while special cause variation is due to external factors

• Common cause variation is due to external factors, while special cause variation is inherent

What is the main aim of SPC?

• To eliminate all defects

• To automate the production process

• To detect and reduce process variability

• To increase the number of products

What type of data do variable data control charts handle?

• Data that can be measured on a continuous scale

• Categorical data

• Binary data

• Nominal data

What is the purpose of an X-bar and R chart?

• To monitor the mean and range of a process

• To track the count of defects per unit

• To display the frequency of defects

• To monitor the proportion of defective items

How are control limits typically set in SPC?

• At four standard deviations above and below the process mean

• At three standard deviations above and below the process mean

• At two standard deviations above and below the process mean

• At one standard deviation above and below the process mean

• The sample was within the control limits.

• The sample was outside the control limits.

• The upper control limit was 0.073.

• The lower control limit was -0.01

An X bar and R chart was prepared for an operation using 25 samples with six pieces in each sample. X double bar was found to be 12.68 and s bar was 2.45. During production, a sample of six was taken and the pieces measured 11, 13, 14, 14, 10 and 12. At the time this sample was taken:

• Both the average and standard deviation were within the control limits.

• Neither the average nor standard deviation were within the control limits.

• Only the average was outside the control limits.

• Only the standard deviation was outside the control limits.