Question 1

Total process variation is made up of the sum of common cause variation and special cause variation.

Accepted Answer

A) True 
 B)False  True

Question 2

Explain the relationship between control limits and specification limits.

Accepted Answer

Control limits are computed from data collected from the actual process.These control limits define the range of inherent variation in the process as it actually exists.The key is they are computed from the data.Managers do not get to determine what these limits are.They have nothing directly to do with the product specifications.On the other hand,specification limits are the range within which the product of service is considered to be acceptable quality.The specification limits are set by the customer,by management,or by engineers based on what defines a quality product.These limits have no direct relationship to how the process may actually be performing other than they represent the range within which we hope all product or service measurements fall.Thus,it is very possible for a process to be deemed to be in control yet be producing a product that is not within specifications.

Question 3

Each evening,a nationwide retail chain randomly calls 100 of the customers who came to their store that day to ask whether they were satisfied with the service they had received.The customers respond yes or no.Suppose the company has found over time that 8 percent of the customers are not satisfied ("no" answers).If they have established a process control chart,what conclusion should be reached if the percentage of customers surveyed tonight that say no is 14 percent?

Accepted Answer

A) This result indicates that a special cause situation exists. 
B) Although this point is above the upper control limit,there is no cause for alarm if this is the first time. 
C) While this value is higher than "normal," it is still within the range of common cause variation and no action is needed. 
D) This is outside the control limits and action should be taken 
A) This result indicates that a special cause situation exists. 
B) Although this point is above the upper control limit,there is no cause for alarm if this is the first time. 
C) While this value is higher than "normal," it is still within the range of common cause variation and no action is needed. 
D) This is outside the control limits and action should be taken C

Question 4

In most processes,the process control limits are set to correspond with the specification limits on the product.

Accepted Answer

A) True 
 B)False

Question 5

If a process control chart has only one point outside the upper or lower control limits,there is insufficient evidence to conclude that the process was out of control at the time that the measurement was taken.

Accepted Answer

A) True 
 B)False

Question 6

A plywood manufacturer is interested in monitoring the thickness of the plywood.Which of the following would be most useful for doing this?

Accepted Answer

A) p-charts 
B) c-charts 
C)   
-charts 
D) Histograms 
A) p-charts 
B) c-charts 
C)   
-charts 
D) Histograms

Question 7

A company that fills soft drinks into bottles has established an   -chart and an R-chart to monitor the average fill level in the bottles.To do this,the company has taken a series of samples of size n = 4 bottles.The overall average fill is 12.03 ounces.The average range for the subgroups has been .06 ounces.Suppose,after developing the control chart,a subgroup of size 4 yields a sample mean of 12.09 ounces and a range of .08,which of the following statements is true?

Accepted Answer

A) The process is in control on both the  
-chart and the R-chart. 
B) The process is out of control on the R-chart but in control on the  
-chart. 
C) The process is out of control on the  
-chart but in control on the R-chart. 
D) The process is out of control on both the   
A) The process is in control on both the  
-chart and the R-chart. 
B) The process is out of control on the R-chart but in control on the  
-chart. 
C) The process is out of control on the  
-chart but in control on the R-chart. 
D) The process is out of control on both the

Question 8

One of the roles of managers who are overseeing the statistical process control analysis is to set the control limits at the desired levels prior to collecting data from the process.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following is not among the most common sources of variation?

Accepted Answer

A) People 
B) Materials 
C) Methods 
D) Quotas 
A) People 
B) Materials 
C) Methods 
D) Quotas

Question 10

Statistical Process Control charts are used to detect whether a process remains in control or whether it has gone out of control.Explain how the SPC signals work.

Accepted Answer

The control limits on an SPC chart are t

Question 11

We expect virtually all the data in a stable process to fall within 2 standard deviations of the mean.

Accepted Answer

A) True 
 B)False

Question 12

When discussing variation in the output of a process,which of the following is not true?

Accepted Answer

A) Variation is natural. 
B) No two products or services are exactly the same. 
C) With a fine enough measurement gauge,all things can be seen to differ. 
D) Common cause variation can be eliminated. 
A) Variation is natural. 
B) No two products or services are exactly the same. 
C) With a fine enough measurement gauge,all things can be seen to differ. 
D) Common cause variation can be eliminated.

Question 13

The x-bar chart is based on the principles of which distribution?

Accepted Answer

A) t-distribution 
B) Chi square distribution 
C) F distribution 
D) Normal distribution 
A) t-distribution 
B) Chi square distribution 
C) F distribution 
D) Normal distribution

Question 14

Because variations are unavoidable in a system,the output of the system is always unpredictable.

Accepted Answer

A) True 
 B)False

Question 15

Variation exists naturally in the world around us so all processes and products can be expected to vary.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following is not a type of commonly used process control chart?

Accepted Answer

A) x-bar chart 
B) R-chart 
C) p-chart 
D) n-chart 
A) x-bar chart 
B) R-chart 
C) p-chart 
D) n-chart

Question 17

It is entirely possible for the R-chart to show that a process is in statistical control and the   -chart to show that the same process is out of control.

Accepted Answer

A) True 
 B)False

Question 18

A stable process is one that has had all its variation removed through quality improvement efforts on the part of the organization.

Accepted Answer

A) True 
 B)False

Question 19

The main process change that can be detected with a process control chart is:

Accepted Answer

A) the process average has shifted up or down from normal. 
B) the process average is trending up or down from normal. 
C) the process is behaving in such a manner that the existing variation is not random in nature. 
D) All of the above 
A) the process average has shifted up or down from normal. 
B) the process average is trending up or down from normal. 
C) the process is behaving in such a manner that the existing variation is not random in nature. 
D) All of the above

Question 20

A p-chart is useful for:

Accepted Answer

A) analyzing whether a process for a measurable variable is in or out of control. 
B) analyzing processes which yield attribute data. 
C) determining what the most likely cause of defects is. 
D) All of the above 
A) analyzing whether a process for a measurable variable is in or out of control. 
B) analyzing processes which yield attribute data. 
C) determining what the most likely cause of defects is. 
D) All of the above

Total process variation is made up of the sum of common cause variation and special cause variation.

Explain the relationship between control limits and specification limits.

In most processes,the process control limits are set to correspond with the specification limits on the product.

If a process control chart has only one point outside the upper or lower control limits,there is insufficient evidence to conclude that the process was out of control at the time that the measurement was taken.

A plywood manufacturer is interested in monitoring the thickness of the plywood.Which of the following would be most useful for doing this?

One of the roles of managers who are overseeing the statistical process control analysis is to set the control limits at the desired levels prior to collecting data from the process.

Which of the following is not among the most common sources of variation?

Statistical Process Control charts are used to detect whether a process remains in control or whether it has gone out of control.Explain how the SPC signals work.

We expect virtually all the data in a stable process to fall within 2 standard deviations of the mean.

When discussing variation in the output of a process,which of the following is not true?

The x-bar chart is based on the principles of which distribution?

Because variations are unavoidable in a system,the output of the system is always unpredictable.

Variation exists naturally in the world around us so all processes and products can be expected to vary.

Which of the following is not a type of commonly used process control chart?

It is entirely possible for the R-chart to show that a process is in statistical control and the -chart to show that the same process is out of control.

A stable process is one that has had all its variation removed through quality improvement efforts on the part of the organization.

The main process change that can be detected with a process control chart is:

A p-chart is useful for:

The Where,Why,and How of Data Collection

Graphs,Charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Introduction to Continuous Probability Distributions

Introduction to Sampling Distributions

Estimating Single Population Parameters

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Introduction to Linear Regression and Correlation Analysis

Multiple Regression Analysis and Model Building

Analyzing and Forecasting Time-Series Data

Introduction to Nonparametric Statistics

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Exam 18: Introduction to Quality and Statistical Process Control

Total process variation is made up of the sum of common cause variation and special cause variation.

Explain the relationship between control limits and specification limits.

In most processes,the process control limits are set to correspond with the specification limits on the product.

If a process control chart has only one point outside the upper or lower control limits,there is insufficient evidence to conclude that the process was out of control at the time that the measurement was taken.

A plywood manufacturer is interested in monitoring the thickness of the plywood.Which of the following would be most useful for doing this?

One of the roles of managers who are overseeing the statistical process control analysis is to set the control limits at the desired levels prior to collecting data from the process.

Which of the following is not among the most common sources of variation?

Statistical Process Control charts are used to detect whether a process remains in control or whether it has gone out of control.Explain how the SPC signals work.

We expect virtually all the data in a stable process to fall within 2 standard deviations of the mean.

When discussing variation in the output of a process,which of the following is not true?

The x-bar chart is based on the principles of which distribution?

Because variations are unavoidable in a system,the output of the system is always unpredictable.

Variation exists naturally in the world around us so all processes and products can be expected to vary.

Which of the following is not a type of commonly used process control chart?

It is entirely possible for the R-chart to show that a process is in statistical control and the -chart to show that the same process is out of control.

A stable process is one that has had all its variation removed through quality improvement efforts on the part of the organization.

The main process change that can be detected with a process control chart is:

A p-chart is useful for:

The Where,Why,and How of Data Collection

Graphs,Charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Introduction to Continuous Probability Distributions

Introduction to Sampling Distributions

Estimating Single Population Parameters

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Introduction to Linear Regression and Correlation Analysis

Multiple Regression Analysis and Model Building

Analyzing and Forecasting Time-Series Data

Introduction to Nonparametric Statistics

Filters