Deck 12: Statistically Based Quality Improvement for Attributes

Question 1

________ attributes relate to the physical characteristics of a particular product or service.

A) Structural
B) Sensory
C) Performance
D) Temporal
E) Ethical

Answer 1

A

Question 2

________ attributes relate to whether or not a particular product or service performs as it is supposed to.

A) Structural
B) Sensory
C) Performance
D) Temporal
E) Ethical

Answer 2

C

Question 3

Attribute charts are developed and interpreted the same way as variables charts.

Answer 3

True

Question 4

A quality engineer notes that a process produces data that are binomial and has been obtained using a sample space that is constant. The primary interest of the process manager is in the percentage of bad parts. An appropriate control chart to use would be a(n) ________.

A) p chart
B) r chart
C) c chart
D) u chart
E) d chart

Question 5

________ attributes relate to time.

A) Structural
B) Sensory
C) Performance
D) Temporal
E) Tactile

Question 6

Production-related attributes are more important to quality managers than customer-based attributes.

Question 7

A quality engineer notes that a process produces data that are binomial and has been obtained using a sample space that is not constant. The primary interest of the process manager is in the percentage of bad parts. An appropriate control chart to use would be a(n) ________.

A) np chart
B) p chart
C) c chart
D) u chart
E) d chart

Question 8

________ attributes relate to senses of touch, smell, taste, and sound.

A) Structural
B) Sensory
C) Performance
D) Consensual
E) Ethical

Question 9

A painter paints a wall and when too much paint is applied, drips result. In the language of attribute charts, the drips are ________.

A) defectives
B) defects
C) variables
D) critical
E) temporal

Question 10

An attribute is a continuous measurement such as weight, height, or volume.

Question 11

Attributes that are more internal and engineering-oriented are called ________ attributes.

A) structural
B) sensory
C) performance
D) customer-based
E) production-related

Question 12

A quality engineer notes that a process produces data that are binomial and has been obtained using a sample space that is not constant. The primary interest of the process manager is in the number of discrepancies per part. An appropriate control chart to use would be a(n) ________.

A) np chart
B) p chart
C) c chart
D) u chart
E) d chart

Question 13

Structural attributes have to do with physical characteristics of a particular product or service.

Question 14

A painting contractor wishes to compare the work done by several painters in several rooms of varying sizes. If the contractor is concerned about drips and missed spots, an np chart would be the logical choice.

Question 15

Customer-based attributes are internal and engineering-oriented.

Question 16

Sensory attributes relate to whether or not a particular product or service performs as it is supposed to.

Question 17

State the five types of attributes.

Question 18

The atmosphere and other aspects of a customer's experience in a hotel would be examples of sensory attributes.

Question 19

________ attributes answer whether a service provider is empathetic or if their accounting systems report properly.

A) Structural
B) Sensory
C) Performance
D) Temporal
E) Ethical

Question 20

The first step in developing an attribute process chart is to ________.

A) determine whether the critical product characteristic is a variable or an attribute
B) establish control limits
C) identify critical product characteristics
D) identify critical operations where process inspection might be needed
E) select the appropriate process chart from the many types of charts

Question 21

Use the following table to answer the question(s) below.

The producers of the Yugo automobile periodically inspect samples of 80 hoods for dents and scratches. A single flaw in a hood renders it unsuitable for installation in one of their fine automobiles. The results of the last 10 samples are shown. Calculate the standard error, s_np, for the np chart.

A) 7.75
B) 0.10
C) 0.31
D) 2.78
E) 2.95

Question 22

An irregularity or problem with a larger unit is a(n) ________.

A) defect
B) defective
C) flaw
D) mistake
E) error

Question 23

A unit that, as a whole, is not acceptable or does not meet performance requirements is a(n) ________.

A) defect
B) defective
C) flaw
D) mistake
E) error

Question 24

Describe the differences between a defect and a defective. Provide an example of each and identify the types of process charts that would monitor defects and defectives.

Question 25

A p chart can be used whether or not there is a constant sample size.

Question 26

A winemaker tastes several 750 ml bottles of varying vintages. A good choice for such a test would be a c chart.

Question 27

Use the following table to answer the question(s) below.

A producer of contact lenses regularly takes samples of 100 lenses and inspects them for scratches. If a lens has a single scratch, it cannot be sold. The results of 10 samples are shown. What is the average proportion defective?

A) 0.012
B) 0.014
C) 0.020
D) 0.028
E) 0.035

Question 28

Use the following table to answer the question(s) below.

A manufacturer of FAX machines checks samples of 50 units for functionality at the conclusion of the assembly process. The results of 10 samples are shown. What is the average proportion defective?

A) 0.07
B) 0.14
C) 0.21
D) 0.28
E) 0.35

Question 29

Which of the following is not used for monitoring defects or defectives?

A) p charts
B) np charts
C) u charts
D) c charts
E) r charts

Question 30

A manufacturer of FAX machines checks samples of 50 units for functionality at the conclusion of the assembly process. The results of 10 samples are shown below: What sample is out of control?

A) 1
B) 2
C) 3
D) 4
E) none of the above

Question 31

Use the following table to answer the question(s) below.

A parks and recreation worker counts the number of paint drips on each standard size park bench. The results from the last 10 benches are shown. If the Parks Department decides to make a c chart, what bench number is out of control?

A) 1
B) 3
C) 5
D) 7
E) none of the above

Question 32

What are the steps required to develop an attribute control chart?

Question 33

An insurance claims department employs 10 claims adjusters who spend all day verifying that forms are valid and have been completed correctly. Forms with mistakes are useless and must be returned to the adjuster who must contact the customer again and resubmit the claim. The supervisor reviews two claims processed by each employee to verify that the process is working at acceptable levels.
How should the process be monitored? Explain your reasoning.

Question 34

A producer of contact lenses regularly takes samples of 100 lenses and inspects them for scratches. If a lens has a single scratch, it cannot be sold. The results of 10 samples are shown. What sample is out of control?

A) 2
B) 4
C) 6
D) 8
E) none of the above

Question 35

Determining whether a critical product characteristic is a variable or attribute is one of the steps in developing a process chart.

Question 36

The producers of the Yugo automobile periodically inspect samples of 80 hoods for dents and scratches. A single flaw in a hood renders it unsuitable for installation in one of their fine automobiles. The results of the last 10 samples are shown. What sample is out of control?

A) 1
B) 3
C) 5
D) 4
E) 10

Question 37

Which of the following is an example of a statistic based on an attribute?

A) s (standard deviation)
B) R (range)
C) p (proportion defective)
D) MR (moving range)
E) X bar (process population average)

Question 38

A defect is an irregularity or problem with a larger unit.

Question 39

What are attribute charts used for and how do they work?

Question 40

Defectives are monitored using ________.

A) c charts
B) g charts
C) u charts
D) p charts
E) d charts

Question 41

What is a u chart and how is it similar to or different than a c chart?

Question 42

System unreliability is increased with ________.

A) a redundant system
B) a parallel system
C) a backup system
D) high reliability components
E) low reliability components

Question 43

Use the following table to answer the question(s) below.

A producer of contact lenses regularly takes samples of 100 lenses and inspects them for scratches. If a lens has a single scratch, it cannot be sold. The results of 10 samples are shown. What are the lower and upper 3-sigma control limits?

A) (-0.021, 0.012)
B) (-0.021, 0.000)
C) (0.012, 0.035)
D) (0.000, 0.035)
E) (0.000, 0.049)

Question 44

A system is composed of three components. Two of the items are in parallel and have reliabilities of 0.95 and 0.90. The third item has a reliability of 0.98 and this item is in series with the first combination. What is the overall system reliability?

A) 0.995
B) 0.985
C) 0.975
D) 0.965
E) 0.955

Question 45

The producers of the Yugo automobile periodically inspect samples of 80 hoods for dents and scratches. A single flaw in a hood renders it unsuitable for installation in one of their fine automobiles. The results of the last 10 samples are shown.. What are the lower and upper control limits for the np chart?

A) (-8.35, 2.8)
B) (2.8, 8.35)
C) (0.3, 17.1)
D) (8.7, 17.1)
E) (0.4, 8.7)

Question 46

Reliability models assume statistical independence between failure events. This means that ________.

A) components do not fail
B) if one component fails, the entire system fails
C) parallel systems are unnecessary
D) the failure of one component does not influence another to fail
E) series systems are unnecessary

Question 47

The u chart is a graph of the number of defects per unit.

Question 48

A parks and recreation worker counts the number of paint drips on each standard size park bench. The results from the last 10 benches are shown. If the Parks Department decides to make a c chart, what should the lower and upper 3-sigma control limits be?

A) (-9.2, 9.2)
B) (0.0, 20)
C) (0.1, 18.3)
D) (3.1, 13.1)
E) (3.1, 18.3)

Question 49

What is a np chart and how is it similar to or different than a p chart?

Question 50

Use the following table to answer the question(s) below.

The producers of the Yugo automobile periodically inspect samples of 80 hoods for dents and scratches. A single flaw in a hood renders it unsuitable for installation in one of their fine automobiles. The results of the last 10 samples are shown.. What is the center line for the np chart?

A) 2.4
B) 5.8
C) 7.2
D) 8.7
E) 10.1

Question 51

Use the following table to answer the question(s) below.

A manufacturer of FAX machines checks samples of 50 units for functionality at the conclusion of the assembly process. The results of 10 samples are shown. What are the lower and upper 3-sigma control limits?

A) (-0.01, 0.09)
B) (-0.01, 0.00)
C) (-0.01, 0.29)
D) (0.00, 0.09)
E) (0.00, 0.29)

Question 52

An np chart can be used whether or not the sample sizes are the same.

Question 53

The np chart is a graph of the number of defectives in a subgroup.

Question 54

The horizontal axis on the bathtub function is ________.

A) failure rate
B) time
C) useful life
D) design reliability
E) predicted life

Question 55

Use the following table to answer the question(s) below.

A parks and recreation worker counts the number of paint drips on each standard size park bench. The results from the last 10 benches are shown. If the Parks Department decides to make a c chart, what should the center line be?

A) 6.9
B) 8.4
C) 9.2
D) 10.7
E) 11.3

Question 56

The p chart is a process chart that is used to graph the proportion of items in a sample that are defective.

Question 57

The vertical axis on the bathtub function is ________.

A) failure rate
B) time
C) predicted life
D) design reliability
E) useful life

Question 58

The shape of the process line in a p chart and an np chart plot is always identical if the same data are used.

Question 59

The lower control limit for a p chart cannot be lower than zero.

Question 60

The reliability model that shows that products are more likely to fail either very early in their useful life or very late in their useful life is called the ________.

A) half-moon hazard function
B) saucer-shaped hazard function
C) half-circle hazard function
D) cone-shaped hazard function
E) bathtub-shaped hazard function

Question 61

Fifty defibrillators are tested for 48 hours per machine. Of all the machines tested, 2 experience malfunctions during the test. What is the failure rate for the machines?

A) 0.004
B) 0.042
C) 0.01
D) 0.008
E) 0.0008

Question 62

What is the reliability of a product with a failure rate of 0.001 per operating hour and a useful life of 1500 hours?

A) 0.14
B) 0.22
C) 0.50
D) 0.78
E) 0.86

Question 63

What is the system availability for something that has a mean time between failures of 50 hours and needs an average of 1 hour to repair when it does fail?

A) 0.98
B) 0.92
C) 0.86
D) 0.80
E) 0.74

Question 64

A system is to be composed of 4 identical components in series. What is the lowest reliability component that can be used in order to have an overall system reliability of 0.85?

A) 0.93
B) 0.94
C) 0.95
D) 0.96
E) 0.97

Question 65

What is the system availability for something that has a mean time between failures of 168 hours and needs an average of 48 hours to repair when it does fail?

A) 0.98
B) 0.93
C) 0.88
D) 0.83
E) 0.78

Question 66

A system is to be composed of 5 identical components in series. What is the lowest reliability component that can be used in order to have an overall system reliability of 0.90?

A) 0.98
B) 0.97
C) 0.96
D) 0.95
E) 0.94

Question 67

What is the reliability of a product with a failure rate of 0.002 per operating hour and a useful life of 1000 hours?

A) 0.14
B) 0.22
C) 0.50
D) 0.78
E) 0.86

Question 68

A system is to be composed of 10 identical components in series. What is the lowest reliability component that can be used in order to have an overall system reliability of 0.90?

A) 0.99
B) 0.98
C) 0.97
D) 0.96
E) 0.95

Question 69

What is the useful life in hours for a product having a reliability of 0.999 and a failure rate of 0.015 failures per hour?

A) 400
B) 420
C) 440
D) 460
E) 480

Question 70

Fifty crash helmets are tested for one hundred hours per helmet. Of all the helmets tested, only one experiences a malfunction during the test. What is the failure rate for the helmets?

A) 0.0002
B) 0.002
C) 0.004
D) 0.0008
E) 0.016

Question 71

What is the system availability for something that has a mean time between failures of 100 hours and needs an average of 4 hours to repair when it does fail?

A) 0.98
B) 0.92
C) 0.96
D) 0.90
E) 0.84

Question 72

A system is composed of three components in series having reliabilities of 0.85, 0.92, and 0.90. What is the overall system reliability?

A) 0.90
B) 0.85
C) 0.80
D) 0.75
E) 0.70

Question 73

What is the approximate useful life in hours for a product having a reliability of 0.9978 and a failure rate of 0.001 failures per hour?

A) 6120
B) 5600
C) 5000
D) 4400
E) 3800

Question 74

A system is composed of three components in series having reliabilities of 0.99, 0.95, and 0.90. What is the overall system reliability?

A) 0.95
B) 0.90
C) 0.85
D) 0.80
E) 0.75

Question 75

Two components of reliability 0.95 are in parallel and this subsystem is connected in series to a component with a reliability of 0.95. The overall system reliability is ________.

A) 0.93
B) 0.94
C) 0.95
D) 0.96
E) 0.97

Question 76

What is the useful life in hours for a product having a reliability of 0.985 and a failure rate of 0.015 failures per hour?

A) 120
B) 200
C) 280
D) 360
E) 440

Question 77

What is the reliability of a product with a failure rate of 0.015 per operating hour and a useful life of 250 hours?

A) 0.14
B) 0.12
C) 0.88
D) 0.98
E) 0.02

Question 78

Two components of reliability 0.95 are in parallel and this subsystem is connected in series to a component with a reliability of 0.90. The overall system reliability is ________.

A) 0.82
B) 0.84
C) 0.86
D) 0.88
E) 0.90

Question 79

A system is composed of three components in series having reliabilities of 0.99, 0.98, and 0.97. What is the overall system reliability?

A) 0.97
B) 0.96
C) 0.95
D) 0.94
E) 0.93

Question 80

Two components of reliability 0.90 are in parallel and this subsystem is connected in series to a component with a reliability of 0.95. The overall system reliability is ________.

A) 0.93
B) 0.94
C) 0.95
D) 0.96
E) 0.97