Question 1

The Taguchi loss function suggests that the capability ratio can be improved by extending the spread between LCL and UCL.

Accepted Answer

A) True 
 B)False  False

Question 2

The assurance that processes are performing in an acceptable manner is the focus of:

Accepted Answer

A)  variability analysis. 
B)  inspection. 
C)  capability assessment. 
D)  quality control. 
E)  acceptance sampling. 
A)  variability analysis. 
B)  inspection. 
C)  capability assessment. 
D)  quality control. 
E)  acceptance sampling. D

Question 3

Control limits tend to be wider for more variable processes.

Accepted Answer

A) True 
 B)False  True

Question 4

Tolerances represent the control limits we use on the charts.

Accepted Answer

A) True 
 B)False

Question 5

Acceptance sampling, when it is used, is used:
(I) before production.
(II) during production.
(III) after production.

Accepted Answer

A)  I only 
B)  I and III only 
C)  I and II only 
D)  II and III only 
E)  I, II, and III 
A)  I only 
B)  I and III only 
C)  I and II only 
D)  II and III only 
E)  I, II, and III

Question 6

A quality analyst wants to construct a control chart for determining whether three machines, all producing the same product, are in control with regard to a particular quality variable. Accordingly, he sampled four units of output from each machine, with the following results: $$\begin{array} { c c c c c } 
\text { Machine } && { \text { Measurements } } \
\hline \# 1 & 17 & 15 & 15 & 17 \
\# 2 & 16 & 25 & 18 & 25 \
\# 3 & 23 & 24 & 23 & 22
\end{array}$$
What are the x-bar chart three-sigma upper and lower control limits?

Accepted Answer

A)  22 and 18 
B)  23.29 and 16.71 
C)  23.5 and 16.5 
D)  23.16 and 16.84 
E)  24 and 16 
A)  22 and 18 
B)  23.29 and 16.71 
C)  23.5 and 16.5 
D)  23.16 and 16.84 
E)  24 and 16

Question 7

The output of a process may not conform to specifications even though the process may be statistically "in control."

Accepted Answer

A) True 
 B)False

Question 8

When a process is not centered, its capability is measured in a slightly different way. The symbol for this case is Cpk.

Accepted Answer

A) True 
 B)False

Question 9

High-cost, low-volume items often require careful inspection since we may have large costs associated with passing defectives.

Accepted Answer

A) True 
 B)False

Question 10

A quality analyst wants to construct a control chart for determining whether four machines, all producing the same product, are in control with regard to a particular quality attribute. Accordingly, she inspected 1,000 units of output from each machine in random samples, with the following results: $$\begin{array} { c c } 
\text { Machine } & \text { Total Defectives } \
\hline \# 1 & 23 \
\# 2 & 15 \
\# 3 & 29 \
\# 4 & 13
\end{array}$$
For upper and lower control limits of .026 and .014, which machine(s), if any, appear(s) to be out-of-control for process proportion of defectives?

Accepted Answer

A)  machine #3 
B)  machine #4 
C)  machines #3 and #4 
D)  machines #2 and #3 
E)  none of the machines 
A)  machine #3 
B)  machine #4 
C)  machines #3 and #4 
D)  machines #2 and #3 
E)  none of the machines

Question 11

A point which is outside of the lower control limit on an R-chart:

Accepted Answer

A)  is an indication that no cause of variation is present. 
B)  should be ignored because it signifies better-than-average quality. 
C)  should be investigated because an assignable cause of variation might be present. 
D)  should be ignored unless another point is outside that limit. 
E)  is impossible since the lower limit is always zero. 
A)  is an indication that no cause of variation is present. 
B)  should be ignored because it signifies better-than-average quality. 
C)  should be investigated because an assignable cause of variation might be present. 
D)  should be ignored unless another point is outside that limit. 
E)  is impossible since the lower limit is always zero.

Question 12

Run tests give managers an alternative to control charts; they are quicker and cost less.

Accepted Answer

A) True 
 B)False

Question 13

Inspection is a(n)_____________ activity.

Accepted Answer

A)  prevention. 
B)  capability analysis. 
C)  flawless 
D)  corrective. 
E)  appraisal. 
A)  prevention. 
B)  capability analysis. 
C)  flawless 
D)  corrective. 
E)  appraisal.

Question 14

The primary purpose of statistical process control is to detect a defective product before it is shipped to a customer.

Accepted Answer

A) True 
 B)False

Question 15

A lower control limit must by definition be a value less than an upper control limit.

Accepted Answer

A) True 
 B)False

Question 16

A time-ordered plot of sample statistics is called a(n) ______ chart.

Accepted Answer

A)  statistical 
B)  inspection 
C)  control 
D)  simo 
E)  limit 
A)  statistical 
B)  inspection 
C)  control 
D)  simo 
E)  limit

Question 17

If a point on a control chart falls outside one of the control limits, this suggests that the process output is nonrandom and should be investigated.

Accepted Answer

A) True 
 B)False

Question 18

A quality analyst wants to construct a control chart for determining whether three machines, all producing the same product, are in control with regard to a particular quality variable. Accordingly, he sampled four units of output from each machine, with the following results: $$\begin{array} { c c c c c } 
\text { Machine } && { \text { Measurements } } \
\hline \# 1 & 17 & 15 & 15 & 17 \
\# 2 & 16 & 25 & 18 & 25 \
\# 3 & 23 & 24 & 23 & 22
\end{array}$$
What is the estimate of the sample average range based upon this limited sample?

Accepted Answer

A)  13.0 
B)  4.33 
C)  5.4 
D)  4.2 
E)  2.0 
A)  13.0 
B)  4.33 
C)  5.4 
D)  4.2 
E)  2.0

Question 19

The traditional view is that the optimum level of inspection occurs when we catch at least 98.6 percent of the defects.

Accepted Answer

A) True 
 B)False

Question 20

A p-chart would be used to monitor:

Accepted Answer

A)  average shrinkage. 
B)  dispersion in sample data. 
C)  the fraction defectivE. 
D)  the number of defects per unit. 
E)  the range of values. 
A)  average shrinkage. 
B)  dispersion in sample data. 
C)  the fraction defectivE. 
D)  the number of defects per unit. 
E)  the range of values.

Exam 14: Quality Control

The Taguchi loss function suggests that the capability ratio can be improved by extending the spread between LCL and UCL.

The assurance that processes are performing in an acceptable manner is the focus of:

Control limits tend to be wider for more variable processes.

Tolerances represent the control limits we use on the charts.

Acceptance sampling, when it is used, is used: (I) before production. (II) during production. (III) after production.

The output of a process may not conform to specifications even though the process may be statistically "in control."

When a process is not centered, its capability is measured in a slightly different way. The symbol for this case is Cpk.

High-cost, low-volume items often require careful inspection since we may have large costs associated with passing defectives.

A point which is outside of the lower control limit on an R-chart:

Run tests give managers an alternative to control charts; they are quicker and cost less.

Inspection is a(n)_____________ activity.

The primary purpose of statistical process control is to detect a defective product before it is shipped to a customer.

A lower control limit must by definition be a value less than an upper control limit.

A time-ordered plot of sample statistics is called a(n) ______ chart.

If a point on a control chart falls outside one of the control limits, this suggests that the process output is nonrandom and should be investigated.

The traditional view is that the optimum level of inspection occurs when we catch at least 98.6 percent of the defects.

A p-chart would be used to monitor:

Introduction to Operations Management

Competitiveness

Forecasting

Product and Service Design

RELIABILITY – Static

Strategic Capacity Planning for Products and Services

Decision Theory– Static

Process Selection and Facility Layout

Work Design and Measurement

learning curve– Static

Location Planning and Analysis

The Transportation Model– Static

Management of Quality

Acceptance Sampling– Static

Aggregate Planning and Master Scheduling

MRP and ERP

Inventory Management

JIT and Lean Operations

Maintenance– Static

Supply Chain Management

Scheduling

Project Management

Management of Waiting Lines

Linear Programming

Filters