Deck 19: Statistical Process Control and Quality Management

Question 1

Which chart portrays the number of defects per unit of production? _____________

Answer 1

c bar chart

Question 2

Mean charts are designed to determine whether a process is in or out of control based on sample means.

Answer 2

True

Question 3

In acceptance sampling, if the number of defects in a sample is less or equal to the acceptance number, then the incoming lot is accepted.

Answer 3

True

Question 4

If the binomial distribution is used to develop an operating characteristic curve for an acceptance sampling plan, then the trials must be ________________.

Question 5

Assignable causes are usually large in number and random in nature, and they cannot be entirely eliminated.

Question 6

Control charts can be developed for both variables and attributes.

Question 7

In an acceptance sampling plan, what happens to the incoming lot if the number of defective items in the sample is less than or equal to the acceptance number? __________________

Question 8

Quality control charts indicate whether a production process is in-control or out-of-control.

Question 9

Pareto charts are based on the 80-20 rule, which says, 80% of the factors cause 20% of the problem.

Question 10

The purpose of a statistical quality control chart is to identify when assignable causes of variation have entered the production system so that the cause may be identified and corrected.

Question 11

If the binomial distribution is used to develop an operating characteristic curve for an acceptance sampling plan, how many possible outcomes can there be? _______

Question 12

The following are examples of attributes: the width of a cracked weld, the length of time that a relay works; the amount of water in a radiator, the diameter of a tire.

Question 13

A fishbone diagram is used to determine if a process is out of control.

Question 14

In acceptance sampling, usually 100% of the incoming lot is checked.

Question 15

Percent defective charts, which are also known as P charts or p bar charts, show the percent of the production that is or is not acceptable.

Question 16

In acceptance sampling, it is possible that an incoming lot of computer chips contains more defective chips than it should, but it is accepted. In acceptance sampling, what is this probability called? _______

Question 17

There are two general types of causes of variations in manufacturing and service processes: chance and assignable causes.

Question 18

A c bar chart shows the percent of the production that is defective.

Question 19

One purpose of quality control is to reduce the costs associated with producing and delivering poor quality goods and services.

Question 20

In acceptance sampling, there is one unique operating characteristic curve for a specified sampling plan.

Question 21

One of the most important concepts of statistical process control is that no two products are ________________.

Question 22

In a fishbone diagram, "dissatisfied customers" would be an _________ and "slow service" would be a _________.

Question 23

What is another name for the p-bar chart? ______________

Question 24

What is the purpose of a statistical control chart that plots sample means? _______________________________

Question 25

What chart portrays the number of defects per unit? ____________

Question 26

What is the "in control" region of a control chart called? ____________________

Question 27

The measurement of color is an _____________.

Question 28

A fishbone diagram starts with the definition of a problem and explores its possible ________.

Question 29

A Pareto chart is designed to show the ____________ that different types of defects occur in a process.

Question 30

How is the center line of a mean chart labeled? _______

Question 31

A statistical quality control chart that is out-of-control shows what type of variation? _______

Question 32

What variation is due to slight changes in materials or process conditions and is random in nature? ________________

Question 33

Acceptance sampling and control charts may be based on measurements with either ______________ or ___________________.

Question 34

A range chart shows variation of ____________.

Question 35

If the sample ranges fall randomly within the upper and lower control limits, then it can be assumed that the process is ___________.

Question 36

A Pareto chart is useful because it is based on the theory that 80% of the observations are accounted for by 20% of the ________.

Question 37

What causes of variation cannot be entirely eliminated? _____________

Question 38

A fishbone diagram is an ________________ tool.

Question 39

A Pareto chart is typically skewed to the ________________.

Question 40

In what decade were the concepts of statistical quality control developed? _________

Question 41

Samples of 200 parts were taken every day and the number of defectives was counted. What are the upper and lower limits for the percent defective chart?

A) 0.02 and 0
B) 0.2970 and 0
C) 0.0297 and 0
D) 0.0497 and 0

Question 42

What chart helps to identify the relatively few factors that impact the performance of a manufacturing or service process?

A) SPC
B) Pareto analysis
C) Fishbone chart analysis
D) Diagnostic chart

Question 43

Cappelli Inc. designs and manufactures women's apparel using material from various mills. Their acceptance sampling plan states that 20 two inch squares of the incoming material must be carefully checked. If 3 or less squares reveal imperfections, the lot is accepted. What is the probability that an incoming lot from Blufton Mills that contains 40 percent imperfect cloth will be accepted?

A) 0
B) 0.239
C) 0.015
D) 0.0024

Question 44

The technique that tallies types of defects and their frequency is called

A) range charts.
B) Pareto analysis.
C) control charts.
D) fishbone diagram.

Question 45

If a company reports that its quarterly earnings will be between $100 million and $125 million, the range is an example of _________ variation.

A) Chance
B) External
C) Assignable
D) controlled

Question 46

What is the process that insures that a company is producing a quality product or service?

A) Six Sigma
B) Pareto analysis
C) Fishbone chart analysis
D) Diagnostic chart

Question 47

The cause-and-effect chart is an example of a

A) range chart.
B) Pareto chart.
C) control chart.
D) fishbone diagram.

Question 48

A chart used to show the results of a Pareto analysis is a

A) Range chart.
B) Bar chart.
C) Control chart.
D) Fishbone diagram.

Question 49

A fishbone diagram classifies potential causes into categories. What are they?

A) Chance and assignable variation
B) Methods, materials, equipment, and personnel
C) Percent defective and percent non-defective
D) Causes and effects

Question 50

Which probability distribution is used to develop a control chart for sample means?

A) Normal distribution
B) Chi-square distribution
C) Poisson distribution
D) Binomial distribution

Question 51

What type of variation can be reduced, or even eliminated and is usually nonrandom in nature?

A) Chance
B) External
C) Assignable
D) Co-variation

Question 52

If a company reports that its quarterly earnings will be between $100 million and $125 million depending on the consumer demand, consumer demand is an example of ________ variation.

A) Chance
B) External
C) Assignable
D) Standard variation

Question 53

What process investigates the potential causes of an outcome or effect such as poor quality?

A) SPC
B) Pareto analysis
C) Fishbone chart analysis
D) Diagnostic chart

Question 54

A subassembly is inspected and the number of defects recorded. A new group of assemblers began work Monday morning. The number of defects per subassembly for the first 10 they produced was: 3, 2, 0, 5, 4, 6, 0, 7, 7, and 6. What are the upper and lower limits for the c bar chart?

A) 15 and 0
B) 10 and 0
C) 1.12 and 0
D) 6 and -2

Question 55

Equipment failure would be an example of ____________ variation.

A) chance
B) external
C) assignable
D) standard variation

Question 56

Which probability distribution is used to develop a percent defective chart?

A) Normal distribution
B) Chi-square distribution
C) Poisson distribution
D) Binomial distribution

Question 57

A sampling plan states that if 20 incoming transistors are checked and 2 or less defects are found that the lot is accepted. If an incoming lot is 10 percent defective, what is the probability of accepting the lot of transistors?

A) 0
B) 1
C) 0.677
D) 0.333

Question 58

Which probability distribution is used to develop an operating characteristic curve?

A) Normal distribution
B) Chi-square distribution
C) Poisson distribution
D) Binomial distribution

Question 59

A sampling plan states that if 20 incoming bolts are checked and 2 or less defective bolts are discovered the lot will be rejected. If an incoming lot is 10 percent defective, what is the probability of rejecting the lot?

A) 0
B) 1
C) 0.323
D) 0.667

Question 60

What is usually developed to evaluate a sampling plan?

A) Frequency polygon
B) Scatter diagram
C) Operating characteristic curve
D) Simple bar chart

Question 61

Control charts are used to determine if a process is

A) in or out of control.
B) measurable.
C) fixable.
D) testable.

Question 62

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the lower control limit for the mean?

A) 6.738
B) 6.669
C) 6.699
D) 6.255

Question 63

A new machine used in the production of motor mount bolts was put into operation. Five samples of size 100 were randomly selected and the number of defectives in each sample was noted. What is the average percent defective?

A) 2.0%
B) 2.3%
C) 2.6%
D) 2.9%

Question 64

If the upper and lower control limits are set at $\pm$ 3 standard deviations from the mean, we would expect that

A) 99.7% of the sample means are within the control limits
B) 95% of the sample means are within the control limits
C) about 68% of the sample means are within the control limits
D) about 5% of the sample means are outside the control limits

Question 65

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the value of A₂, the control limit factor for averages?

A) 0
B) 1
C) 0.577
D) 0.483

Question 66

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the mean range?

A) 0.000
B) 0.160
C) 0.080
D) 0.203

Question 67

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the range of the samples at 7 am?

A) 0.05
B) 0.06
C) 0.11
D) 0.12

Question 68

A new machine used in the production of motor mount bolts was put into operation. Five samples of size 100 were randomly selected and the number of defectives in each sample was noted. What is the lower control limit (LCL)?

A) 0%
B) -2.2%
C) 4.8%
D) 1.6%

Question 69

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the value of the upper control factor of the range?

A) 0
B) 2.115
C) 2.004
D) 3.0

Question 70

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the value of the lower control factor of the range?

A) 0
B) 2.115
C) 2.004
D) 3.0

Question 71

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is X bar for 7 pm?

A) 6.71
B) 6.72
C) 6.74
D) 6.76

Question 72

A new machine used in the production of motor mount bolts was put into operation. Five samples of size 100 were randomly selected and the number of defectives in each sample was noted. What is the upper control limit (UCL)?

A) 6.7%
B) 7.4%
C) 8.1%
D) 100%

Question 73

In a control chart, expected variation is defined by the

A) standard deviation.
B) standard error of the distribution.
C) only upper control limits.
D) upper and lower control limits.

Question 74

The Quality Assurance Department selected 12 samples of 100 printed circuit boards and tested them. The number of defective printed circuit boards in each sample was 3, 3, 0, 5, 1, 1, 5, 6, 6, 2, 0, and 1. What kind of control chart should be constructed to monitor the process?

A) Mean chart
B) Range chart
C) Percent defective chart
D) C-bar chart

Question 75

The upper and lower control limits are usually set at

A) the mean.
B) above the mean.
C) 3 standard deviations from the mean.
D) 2 standard deviations from the mean.

Question 76

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the range of the samples at 4 pm?

A) 0.05
B) 0.06
C) 0.11
D) 0.12

Question 77

The Quality Assurance Department selected a sample of 12 printed circuit boards and tested them. The number of defects in each circuit board was 3, 3, 0, 5, 1, 1, 5, 6, 6, 2, 0, and 1. What kind of control chart should be constructed to monitor the process?

A) Mean chart
B) Range chart
C) Percent defective chart
D) C-bar chart

Question 78

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the upper control limit (UCL) for the mean?

A) 6.738
B) 6.999
C) 6.777
D) 7.221

Question 79

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is the value for the lower control limit (LCL) of the range?

A) 0.00
B) 0.080
C) 0.186
D) 0.203

Question 80

A new machine is set or calibrated to fill tubes of toothpaste at precisely 6.75 ounces. Then, once the machine is running, a sample of 6 tubes is taken every three hours and weighed with the following results: What is X bar for 7 am?

A) 6.72
B) 6.74
C) 6.78
D) 6.80