Question 1

In statistical process control, the range often substitutes for the standard deviation.

Accepted Answer

A) True 
 B)False

Question 2

Mean charts and range charts complement one another, one detecting shifts in process average, the other detecting shifts in process dispersion.

Accepted Answer

A) True 
 B)False

Question 3

Examine the Statistical Process Control outputs below. Answer the following questions.
a. What is the sample size?
b. What is the number of samples?
c. What is the mean of sample 8; what is the range of sample 10?
d. Is this process in control? Explain-a simple Yes or No is insufficient.
e. What additional steps should the quality assurance team take? $\begin{array}{|l|l|l|l|l|l|l|}
\hline&&\text { Mean } && \text { Range }\
\text { UCL (Upper control limit) }&&12.6856&&1.0193\
\hline\text { CL (Center line) }&&12.36&&0.67\
\text { LCL (Lower control limit) }&&10.0344&&0\
\text { Sample Number }&\text { Item 1 }&\text { Item 2 }&\text { Item 3}&\text { Item 4}&\text { Mean } & \text { Range }\
\hline \text { Sample 1 } & 12.2 & 12.6 & 12 & 12.1 & 12.225 & 0.6 \
\text { Sample 2 } & 11.9 & 12.5 & 12.4 & 12.7 & 12.375 & 0.8 \
\text { Sample 3 } & 12 & 12.2 & 12.9 & 13.1 & 12.55 & 1.1 \
\text { Sample 4 } & 12.5 & 12.5 & 12.4 & 12.8 & 12.55 & 0.4 \
\text { Sample 5 } & 12.2 & 12.8 & 12.7 & 12 & 12.425 & 0.8 \
\text { Sample 6 } & 12.1 & 12.5 & 11.8 & 12.3 & 12.175 & 0.7 \
\text { Sample 7 } & 12.3 & 12.4 & 12.8 & 12.4 & 12.475 & 0.5 \
\text { Sample 8 } & 12 & 12.1 & 12.4 & 12.2 & 12.175 & 0.4 \
\text { Sample 9 } & 12.1 & 12.8 & 12.4 & 11.9 & 12.3 & 0.9 \
\text { Sample 10 } & 12.6 & 12.4 & 12.1 & 12.3 & 12.35 & 0.5 \
\hline
\end{array}$

Accepted Answer

The sample size is 4; ten samples were t

Question 4

A local manufacturer supplies you with parts, and you would like to install a quality monitoring system at his factory for these parts. Historically, the defect rate for these parts has been 1.25% (You've observed this from your acceptance sampling procedures, which you would like to discontinue). Develop ± 3σ control limits for this process. Assume the sample size will be 200 items.

Accepted Answer

p-bar is 0.0125; the standard error of t

Question 5

A Cp of 1.33 indicates how many sigma limits?

Accepted Answer

A)  1 
B)  1.33 
C)  2 
D)  3 
E)  4 
A)  1 
B)  1.33 
C)  2 
D)  3 
E)  4

Question 6

The acceptable quality level (AQL) is the average level of quality we are willing to accept.

Accepted Answer

A) True 
 B)False

Question 7

A manufacturer uses statistical process control to control the quality of the firm's products. Samples of 50 of Product A are taken, and a defective/acceptable decision is made on each unit sampled. For Product B, the number of flaws per unit is counted. What type(s) of control charts should be used?

Accepted Answer

A)  p-charts for A and B 
B)  p-chart for A, c-chart for B 
C)  c-charts for both A and B 
D)  p-chart for A, mean and range charts for B 
E)  c-chart for A, mean and range charts for B 
A)  p-charts for A and B 
B)  p-chart for A, c-chart for B 
C)  c-charts for both A and B 
D)  p-chart for A, mean and range charts for B 
E)  c-chart for A, mean and range charts for B

Question 8

The x-bar chart, like the c-chart, is based on the exponential distribution.

Accepted Answer

A) True 
 B)False

Question 9

What does it mean for a process to be "capable"?

Accepted Answer

Process capability implies tha

Question 10

The statistical definition of Six Sigma allows for 3.4 defects per million. This is achieved by a Cpk index of

Accepted Answer

A)  0. 
B)  1. 
C)  1.33. 
D)  1.67. 
E)  2. 
A)  0. 
B)  1. 
C)  1.33. 
D)  1.67. 
E)  2.

Question 11

A department chair wants to monitor the percentage of failing students in classes in her department. Each class had an enrollment of 50 students last spring. The number of failing students in the 10 classes offered that term were 1, 4, 2, 0, 0, 0, 0, 0, 0, and 3, respectively. Compute the control limits for a p-chart at the 95% confidence level. Is the process in control?

Accepted Answer

From Table S6.2 in the text, the z-value

Question 12

If μ = 9 ounces, σ = 0.7 ounces, and n = 9, calculate the 3-sigma control limits.

Accepted Answer

The answer of If μ = 9 ounces, σ =...

Question 13

Assignable variation

Accepted Answer

A)  is a sign that a process is under control. 
B)  is to be identified and investigated. 
C)  is the same as random variation. 
D)  is variation that cannot be traced to a specific cause. 
E)  leads to a steep Operating Characteristics curve. 
A)  is a sign that a process is under control. 
B)  is to be identified and investigated. 
C)  is the same as random variation. 
D)  is variation that cannot be traced to a specific cause. 
E)  leads to a steep Operating Characteristics curve.

Question 14

The width of a gold bar is intended to be 0.42 cms. Inspection samples contain six bars each. The average range of these samples is 0.007 cms. What are the upper and lower control limits for the x-bar and R-chart for this process, using 3-sigma limits?

Accepted Answer

X-bar: LCL = .4166;

Question 15

A normal distribution is generally described by its two parameters: the mean and the range.

Accepted Answer

A) True 
 B)False

Question 16

The type of inspection that classifies items as being either good or defective is

Accepted Answer

A)  variable inspection. 
B)  attribute inspection. 
C)  fixed inspection. 
D)  all of the above. 
E)  none of the above. 
A)  variable inspection. 
B)  attribute inspection. 
C)  fixed inspection. 
D)  all of the above. 
E)  none of the above.

Question 17

A city police chief decides to do an annual review of the police department by checking the number of monthly complaints. If the total number of complaints in each of the 12 months were 15, 18, 13, 12, 16, 20, 5, 10, 9, 11, 8, and 3 and the police chief wants a 90% confidence level, are the complaints in control?

Accepted Answer

From Table S6.2 in the text, z = 1.65
c-

Question 18

Pierre's Motorized Pirogues and Mudboats is setting up an acceptance sampling plan for the special air cleaners he manufactures for his boats. His specifications, and the resulting plan, are shown on the POM for Windows output below. Pierre wants acceptance sampling to remove ALL defects from his production of air cleaners. Explain carefully why this won't happen.

Accepted Answer

Acceptance sampling is not intended to r

Question 19

An operator trainee is attempting to monitor a filling process that has an overall average of 705 cc. The average range is 17 cc. If you use a sample size of 6, what are the upper and lower control limits for the x-bar and R chart?

Accepted Answer

From table, A₂ = 0.483, D₄ = 2.0

Question 20

Can "in control" and "capable" be shown on the same chart?

Accepted Answer

Only indirectly. The chart illustrating

Exam 26: Statistical Process Control

In statistical process control, the range often substitutes for the standard deviation.

Mean charts and range charts complement one another, one detecting shifts in process average, the other detecting shifts in process dispersion.

A Cp of 1.33 indicates how many sigma limits?

The acceptable quality level (AQL) is the average level of quality we are willing to accept.

The x-bar chart, like the c-chart, is based on the exponential distribution.

What does it mean for a process to be "capable"?

The statistical definition of Six Sigma allows for 3.4 defects per million. This is achieved by a Cpk index of

If μ = 9 ounces, σ = 0.7 ounces, and n = 9, calculate the 3-sigma control limits.

Assignable variation

The width of a gold bar is intended to be 0.42 cms. Inspection samples contain six bars each. The average range of these samples is 0.007 cms. What are the upper and lower control limits for the x-bar and R-chart for this process, using 3-sigma limits?

A normal distribution is generally described by its two parameters: the mean and the range.

The type of inspection that classifies items as being either good or defective is

An operator trainee is attempting to monitor a filling process that has an overall average of 705 cc. The average range is 17 cc. If you use a sample size of 6, what are the upper and lower control limits for the x-bar and R chart?

Can "in control" and "capable" be shown on the same chart?

Operations and Productivity

Operations Strategy in a Global Environment

Project Management

Forecasting

Design of Goods and Services

Managing Quality

Process Strategy and Sustainability

Location Strategies

Layout Strategies

Human Resources, Job Design, and Work Measurement

Supply-Chain Management

Inventory Management

Aggregate Planning

Material Requirements Planning Mrp and Erp

Short-Term Scheduling

Lean Operations

Maintenance and Reliability

Decision-Making Tools

Linear Programming

Transportation Models

Waiting-Line Models

Learning Curves

Simulation

Supply Chain Management Analytics

Sustainability in the Supply Chain

Capacity and Constraint Management

Filters

A C_p of 1.33 indicates how many sigma limits?

The statistical definition of Six Sigma allows for 3.4 defects per million. This is achieved by a C_pk index of