Deck 11: Quality Management Models

Question 1

Process variation, the measurable change in the output of a process:

A)is always subject to elimination.
B)is not management's responsibility.
C)may be uncontrollable.
D)generates output of unacceptable quality.

Answer 1

C

Question 2

Six Sigma refers to plus or minus three standard deviations.

Answer 2

False

Question 3

Deming and some other experts contend that multiple sourcing
impedes the interests of quality because multiple sourcing creates an adversarial relationship between supplier and customer.

Answer 3

True

Question 4

In process control, if there are multiple production lines or
machines, those from which the samples are to be drawn, are to be
selected randomly.

Question 5

Both Deming's 14 points and the Six Sigma concept promote risk taking.

Question 6

Fishbone diagrams are potentially as effective in analyzing
service quality as they are in analyzing product quality.

Question 7

Control charts:

A)rely strictly on multi-item samples.
B)record sample means, ranges, or proportions.
C)deal with numerical measurements, not attributes.
D)help to evaluate products, not processes.

Question 8

When testing sample observations the values ( $\bar { X }$ and R) of the
observations are relevant, but their < b>sequence is not.

Question 9

Walter Shewhart, the developer of control charts, believed quality is associated with consistency of performance.

Question 10

The standard techniques used in attribute quality control may be modified to accommodate unequal sample sizes.

Question 11

Process flow diagrams:

A)are chronological, as opposed to functional.
B)were first developed by K.Ishikawa.
C)generate quality control limits.
D)use PERT/CPM symbols.

Question 12

A fishbone diagram for sources of quality is:

A)applicable to products but not services.
B)chronological, as opposed to functional.
C)diagnostic, not descriptive.
D)a cause-and-effect representation.

Question 13

Fishbone diagrams do not include a category for "software."

Question 14

According to the central limit theorem, sample values follow a normal distribution.

Question 15

In process control, sample ranges may be used to approximate
sample standard deviations

Question 16

The flow in a process flow diagram is functional rather than chronological.

Question 17

In establishing control limits for an R control chart, the lower limit (LCL) is always zero.

Question 18

Multiple (vendor) sourcing typically does not provide:

A)closer supplier/customer relations.
B)downward price pressure.
C)less chance for supply disruption.
D)a heavier quality assurance "burden" for the customer.

Question 19

Deming's points discourage inspection for quality control.

Question 20

Control limits for the mean are symmetrical around $\bar { \bar { X } }$ , and control limits for the range around $\bar { R }$ are also symmetrical.

Question 21

How does the advertising slogan "Quality is Job 1" compare to Deming's 14 points?

Question 22

For $\bar { X }$ charts, a set of eight tests can be used to signify that a process is out of control."Out of control" is indicated if:

A)all eight tests are positive.
B)only one of eight is positive.
C)more than half the tests are positive.
D)half or more tests are "borderline."

Question 23

If a process is to be sampled once each hour, the precise time within the hour:

A)should be the same each hour of operation.
B)should change with shift changes.
C)should be determined randomly.
D)should be incremented on a constant basis.

Question 24

In establishing control limits for $\bar { X }$ charts:

A) $\bar { R }$ is used in the estimation of ?.
B)a two-standard deviation range is typical.
C) is the center line.
D)the range between limits is independent of sample size.

Question 25

The quadratic loss function assumes that any deviation from the ideal measurement for product conformance results in a potential loss to:

A)the environment.
B)society
C)the producer.
D)the consumer.

Question 26

The Deming Prize is awarded to Japanese firms demonstrating significant quality improvements.For whom is it named?

Question 27

The larger the sample size, the more the values of ___________ approach a normal distribution.

A)X
B) $\bar { X }$
C)R
D)(?)

Question 28

Two Rivers Paper Company measures the dampness of the paper rolling off the mill once every minute.If the average of 60 measurements is within specifications, can we say the process is in control?

Question 29

Of the costs relating to quality, probably the most difficult to measure is:

A)production cost.
B)sampling cost.
C)scrap & rework cost.
D)customer satisfaction cost.

Question 30

Which of the following is not a reason to prefer single-item sampling to multi-item sampling?

A)Attributes, not measurements, are being evaluated.
B)Items sampled are necessarily destroyed.
C)Process output is known to be relatively homogeneous.
D)The cost of sampling each item is extremely high.

Question 31

Why are there eight tests for control for $\bar { X }$ charts but only
four for R charts?

Question 32

Additional tests, beyond observing sample data points falling within the specified control limits, are available.None of these additional tests evaluate:

A)consecutive values on the same side of the centerline.
B)consecutive increasing or decreasing values.
C)consecutive oscillating values.
D)consecutive constant values.

Question 33

Over a twenty hour period forty samples of five items each were collected.From this data, the values calculated for $\bar { \bar { X } }$ and $\bar { R }$ were 120.10 and 45.75 respectively.Based on this data, the upper control limit for the X bar control chart should be set at
Approximately:

A)120.10
B)129.43
C)146.49
D)165.85

Question 34

The probability distribution forming the basis for attribute sampling is the ________distribution.

A)multinomial
B)binomial
C)normal
D)t

Question 35

Concerning the construction and use of R control charts:

A) $\bar { R }$ is the centerline.
B)The control range is symmetrical.
C)Positive results are deemed conclusive.
D)Required sample size is different from

Question 36

Which two groups can control process variation?

Question 37

Sources of random error in monitoring a production process for quality control purposes include:

A)miscalibration of measuring devices.
B)transposition of numbers in recording measurements.
C)not sampling from each of multiple production lines.
D)sampling at exactly the same time each hour.

Question 38

Quality management:

A)applies to products more than services.
B)works for measurements, not attributes.
C)always requires random sampling.
D)may suggest 100% inspection.

Question 39

Before an $\bar { X }$ chart can be used properly, the production process should be verified as being under control, as determined by its:

A)central value.
B)variability.
C)distribution.
D)run length.

Question 40

A sample value above the upper control limit (UCL) or below the lower control limit (LCL) calls for:

A)process shutdown.
B)an immediate second sample.
C)additional tests.
D)further investigation.

Question 41

For the initial control charts, the mean and standard deviation were estimated from specifications.After the first results, how would you modify the mean and standard deviation for the $\bar { X }$ and R charts?

Question 42

A full day's quality control tests (24 points) all fall within one standard deviation of the process mean.Why might you deem the process to be "out of control"?

Question 43

Under what conditions can control test 7 (8 consecutive points outside plus or minus one standard deviation) be applied to the X and R_m control charts for single item sampling?

Question 44

A bowling alley checks the timing of the ball returns daily for four lanes.The times are given in seconds.Create X-bar and R charts.Is the process in control? $$\begin{array} { c c c c c } \text { day\ allay \# } & \mathbf { 1 } & \mathbf { 2 } & \mathbf { 3 } & \mathbf { 4 } \\\mathbf { 1 } & 15 & 17 & 15 & 17 \\\mathbf { 2 } & 17 & 16 & 18 & 21 \\\mathbf { 3 } & 16 & 15 & 14 & 16 \\\mathbf { 4 } & 19 & 16 & 19 & 18 \\\mathbf { 5 } & 15 & 17 & 15 & 20 \\\mathbf { 6 } & 15 & 14 & 14 & 19 \\\mathbf { 7 } & 16 & 18 & 17 & 18 \\\mathbf { 8 } & 18 & 15 & 18 & 20 \\\mathbf { 9 } & 15 & 16 & 15 & 17 \\\mathbf {10} & 16 & 16 & 16 & 21\end{array}$$

Question 45

Suppose a manufacturer of canned corn randomly selects five cans of corn each hour and counts the number of kernels in these cans in order to assess quality.For the first thirty hours the average number of kernels in the 150 cans tested was 245.26.The average range for the thirty samples was 12.45.On the basis of this data:A.Determine the upper and lower control limits for the X-bar chart.
B.Determine the upper and lower control limits for the R chart.

Question 46

What entries would you put into a fishbone diagram for Ross' Gardening Service?

Question 47

Quality testing at Jefferson Carpets is expensive but not destructive.You recommend a sample size of 4.Why?

Question 48

Despite extensive quality control efforts, the Model Q sparkplug production line produces plugs with an average defect rate of 4%.Sparkplugs cost $.80 each to produce and the warranty cost for each defective item shipped is estimated to be $2.50.Management is considering the installation of a testing device for
identifying defective sparkplugs.The unit will correctly select
99% of the defective plugs but, unfortunately, will also incorrectly show as defective 5% of the non-defective plugs.Any plug labeled as defective will be discarded.Testing will cost $.025 per sparkplug.
Should the firm install the testing unit?

Question 49

Fifteen random samples of size four yield the following statistics:Sample $\bar { X }$ R Sample $\bar { X }$ R Sample $\bar { X }$ R
$\begin{array} { c c c c c c c c c } 1 & 331 & 8 & 6 & 333 & 4 & 11 & 332 & 6 \\2 & 333 & 5 & 7 & 332 & 13 & 12 & 335 & 7 \\3 & 335 & 8 & 8 & 331 & 5 & 13 & 330 & 7 \\4 & 337 & 7 & 9 & 334 & 6 & 14 & 330 & 5 \\5 & 336 & 9 & 10 & 332 & 9 & 15 & 334 & 6\end{array}$
For these data, determine the upper and lower control limits for the $\bar { X }$ and R charts.

Question 50

Suppose an X-bar chart has a centerline of 10.0 and upper and lower control limits of 16.0 and 4.0 respectively.The sample mean values over the next eight periods are 10.2, 9.3, 11.4, 11.8, 12.7, 14.2, 13.8, and 15.2.Would you conclude that the process is in control during this time frame? If not, which period(s) indicate an out of control process, and which tests are violated?