Question 1

If you are going to develop an X-bar chart based on range statistics and you are using a sample size of 12 for your charting purposes, which of the following is the A2 factor for the X-bar chart?

Accepted Answer

The A2 factor for an X-bar chart with a sample size of 12 is 0.27, which is used to calculate control limits.

Question 2

Other things remaining the same, and assuming that X-bar is smaller than USL and larger than LSL, if the standard deviation (σ) of the process increases, process capability index (Cpk) of the process will

Accepted Answer

Cpk is calculated as the minimum of (USL - X-bar)/(3σ) and (X-bar - LSL)/(3σ). If the standard deviation (σ) increases, the denominator of these fractions increases, leading to a decrease in the Cpk value.

Question 3

Comparing traditional view of the cost of variability and Taguchi's view of cost of variability,
A) Both views are about the same
B) Traditional view holds that as long as the product is within specification, there is no difference.
C) Taguchi's view holds that closer to the midpoint of specifications better it is.
D) None of the above.

Accepted Answer

The answer of Comparing traditional view of the cost of...

Question 4

The International Organization for Standardization (ISO) has written standards that apply to quality management and assurance for businesses. Which of the following are not among the standards ISO has developed?

Accepted Answer

ISO 17000 is not related to the composition of boards of directors; it is related to conformity assessment. ISO does not have a standard specifically for the composition of boards of directors.

Question 5

Consider a sampling plan with n = 40 and c = 1 and given Acceptable quality level (AQL), Lot tolerance percent defective (LTPD), producer's risk (α) and consumer's risk (β). Suppose that c is increased to 2, keeping AQL and LTPD unchanged, consumer's risk (β) will

Accepted Answer

The answer of Consider a sampling plan with n =...

Question 6

You are developing an X-bar chart based on sample means. You know the standard deviation of the sample means is 4, the desired confidence level is 99 percent, and the average of the sample means is 20. Which of the following is your LCL?

Accepted Answer

To find the lower control limit (LCL) for an X-bar chart, we use the formula: 
LCL = X-double-bar - A2 * (sigma / sqrt(n)), where 
X-double-bar = average of the sample means (given as 20) 
A2 = a constant based on the sample size and desired confidence level (looked up from a table or calculated) 
sigma = standard deviation of the sample means (given as 4) 
n = sample size (not given, but assumed to be sufficient)

For a 99 percent confidence level and sample size of 25 or more, the A2 value is 2.78. Plugging in the values: 
LCL = 20 - 2.78 * (4 / sqrt(n))

Since sqrt(n) is not given, we cannot solve for the exact value of LCL. However, we can compare the answer choices to the equation and eliminate any that are clearly incorrect.

Eliminating A and E: 
A) LCL = 20 - 2.78 * (4 / sqrt(1)) = negative value, not possible 
E) LCL = 20 - 2.78 * (4 / sqrt(100)) = 17.68, too high

Eliminating B and D: 
B) LCL = 20 - 2.78 * (4 / sqrt(9)) = 15.12, too low 
D) LCL = 20 - 2.78 * (4 / sqrt(16)) = 18.84, too high

Therefore, the only answer choice that remains is C) LCL = 20 - 2.78 * (4 / sqrt(n)), which is the best choice for the lower control limit.

Question 7

The cause and effect diagram (choose the most inclusive answer.)

Accepted Answer

The answer of The cause and effect diagram (choose the...

Question 8

Consider a sampling plan with n = 40 and c = 2 and given Acceptable quality level (AQL), Lot tolerance percent defective (LTPD), producer's risk (α) and consumer's risk (β). Suppose that c is decreased to 1, keeping AQL and LTPD unchanged, producer's risk (α) will

Accepted Answer

Decreasing the acceptance number c from 2 to 1 makes the sampling plan more stringent, which increases the likelihood of rejecting a lot that meets the AQL, thus increasing the producer's risk (α).

Question 9

Looking outside the organization to examine what industry competitors and excellent performers outside of your industry are doing in a particular process is called:

Accepted Answer

External benchmarking involves analyzing the practices of competitors and top performers in other industries to improve one's own processes.

Question 10

You want to develop a three-sigma R-chart. You know the average range is 5 based on several samples of size 10. Which of the following is the resulting UCL?

Accepted Answer

For a three-sigma R-chart, the Upper Control Limit (UCL) is calculated using the formula UCL = D4 * R-bar, where R-bar is the average range (5 in this case) and D4 is a factor that depends on the sample size. For a sample size of 10, D4 is approximately 2.114. Therefore, UCL = 2.114 * 5 = 10.57, which rounds to approximately 10.6, but since this option is not available, the closest provided option is B) 8.9, indicating a possible mistake in the calculation or in the provided options.

Question 11

You want to develop a three-sigma R-chart. You know the average range is 12 based on several samples of size 6. Which of the following is the resulting LCL?

Accepted Answer

The answer of You want to develop a three-sigma R-chart....

Question 12

DPMO refers to

Accepted Answer

DPMO stands for Defects Per Million Opportunities, meaning the number of defects in a process or product for every million opportunities for a defect to occur. This is typically used as a measure of quality and process improvement in manufacturing and service industries.

Question 13

All except one of the following is an analytical tool for six sigma.

Accepted Answer

All of the listed tools are analytical tools for Six Sigma, so the correct answer is the tool that is not listed. DPMO (Defects per Million Opportunities) analytics are a metric used in Six Sigma to measure the performance of a process and identify improvement opportunities, but it is not a specific tool or diagram like the other options listed.

Question 14

If you are going to develop an R-chart based on range statistics and you are using a sample size of 15 for your charting purposes, which of the following is the upper control limit D4 factor for the chart?

Accepted Answer

The answer of If you are going to develop an...

Question 15

The capability index is:

Accepted Answer

The capability index measures how well a process can produce output within specified limits, calculated as the range of design specifications divided by the range of process output.

Question 16

If you are going to develop an R-chart based on range statistics and you are using a sample size of 9 for your charting purposes, which of the following is the lower control limit D3 factor for the chart?

Accepted Answer

The D3 factor for a sample size of 9 is 0.18.

Quiz 10: Quality Management and Six Sigma