Question 1

Acceptance sampling is usually used to control

Accepted Answer

A)  the number of units output from one stage of a process which are then sent to the next stage 
B)  the number of units delivered to the customer 
C)  the quality of work-in-process inventory 
D)  incoming lots of purchased products 
E)  all of the above 
A)  the number of units output from one stage of a process which are then sent to the next stage 
B)  the number of units delivered to the customer 
C)  the quality of work-in-process inventory 
D)  incoming lots of purchased products 
E)  all of the above

Question 2

In most acceptance sampling plans, when a lot is rejected, the entire lot is inspected and all defective items are replaced. When using this technique the AOQ

Accepted Answer

A)  worsens (AOQ becomes a larger fraction) 
B)  improves (AOQ becomes a smaller fraction) 
C)  is not affected, but the AQL is improved 
D)  is not affected 
E)  falls to zero 
A)  worsens (AOQ becomes a larger fraction) 
B)  improves (AOQ becomes a smaller fraction) 
C)  is not affected, but the AQL is improved 
D)  is not affected 
E)  falls to zero

Question 3

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. In relatively plain English (someone else will translate for Pierre), explain exactly what he will do when performing the acceptance sampling procedure, and what actions he might take based on the results.

Accepted Answer

Pierre should select samples of size 175

Question 4

The p-chart tells us whether there has been a

Accepted Answer

A)  gain or loss in dispersion 
B)  change in the percent defective in a sample 
C)  change in the central tendency of the process output 
D)  change in the number of defects in a sample 
E)  none of the above 
A)  gain or loss in dispersion 
B)  change in the percent defective in a sample 
C)  change in the central tendency of the process output 
D)  change in the number of defects in a sample 
E)  none of the above

Question 5

Mistakes stemming from workers' inadequate training represent an assignable cause of variation.

Accepted Answer

A) True 
 B)False

Question 6

Larry's boat shop wants to monitor the number of blemishes in the paint of each boat. Construct a 3-sigma c-chart to determine if their paint process is in control using the following data.
 $$\begin{array} { | c | c | } 
\hline \begin{array} { c } 
\text { Sample } \
\text { Number }
\end{array} & \begin{array} { c } 
\text { Number of } \
\text { Defects }
\end{array} \
\hline 1 & 3 \
\hline 2 & 4 \
\hline 3 & 2 \
\hline 4 & 1 \
\hline 5 & 3 \
\hline 6 & 2 \
\hline 7 & 1 \
\hline 8 & 4 \
\hline 9 & 2 \
\hline 10 & 3 \
\hline
\end{array}$$

Accepted Answer

11ea4c9a_0

Question 7

X-bar charts are used when we are sampling attributes.

Accepted Answer

A) True 
 B)False

Question 8

In the table below are selected values for the OC curve for the acceptance sampling plan n=210, c=6. Upon failed inspection, defective items are replaced. Calculate the AOQ for each data point. (You may assume that the population is much larger than the sample.) Plot the AOQ curve. At approximately what population defective rate is the AOQ at its worst?
 Explain how this happens. How well does this plan meet the specifications of AQL=0.015, α=0.05; LTPD=0.05, β=0.10?
 Discuss.
 $$\begin{array} { | c | c | } 
\hline 0.00 & 1.00000 \
\hline 0.01 & 0.99408 \
\hline 0.02 & 0.86650 \
\hline 0.03 & 0.55623 \
\hline 0.04 & 0.26516 \
\hline 0.05 & 0.10056 \
\hline 0.06 & 0.03217 \
\hline 0.07 & 0.00905 \
\hline 0.08 & 0.00231 \
\hline 0.09 & 0.00054 \
\hline 0.10 & 0.00012 \
\hline
\end{array}$$

Accepted Answer

The plan meets the α

Question 9

To set $\bar { X }$ -chart upper and lower control limits, one must know the process central line, which is the

Accepted Answer

A)  average of the sample means 
B)  total number of defects in the population 
C)  percent defects in the population 
D)  size of the population 
E)  average range 
A)  average of the sample means 
B)  total number of defects in the population 
C)  percent defects in the population 
D)  size of the population 
E)  average range

Question 10

Which of the following is true regarding the average outgoing quality level?

Accepted Answer

A)  An AOQ value of 1 is ideal, because all defects have been removed. 
B)  AOQ is always greater than AQL but less than LTPD. 
C)  AOQ rises (worsens) following inspection of failed lots. 
D)  AOQ is very low (very good) for extremely poor quality lots. 
E)  None of the above is true. 
A)  An AOQ value of 1 is ideal, because all defects have been removed. 
B)  AOQ is always greater than AQL but less than LTPD. 
C)  AOQ rises (worsens) following inspection of failed lots. 
D)  AOQ is very low (very good) for extremely poor quality lots. 
E)  None of the above is true.

Question 11

McDaniel Shipyards wants to develop control charts to assess the quality of its steel plate. They take ten sheets of 1" steel plate and compute the number of cosmetic flaws on each roll. Each sheet is 20' by 100'. Based on the following data, develop limits for the control chart, plot the control chart, and determine whether the process is in control.
 $$\begin{array} { | c | c | } 
\hline \text { Sheet } & \begin{array} { c } 
\text { Number of } \
\text { flaws }
\end{array} \
\hline 1 & 1 \
\hline 2 & 1 \
\hline 3 & 2 \
\hline 4 & 0 \
\hline 5 & 1 \
\hline 6 & 5 \
\hline 7 & 0 \
\hline 8 & 2 \
\hline 9 & 0 \
\hline 10 & 2 \
\hline
\end{array}$$

Accepted Answer

@#IMG-DLM& 
 @#IMG-DLM& Sample six is ab

Question 12

The Central Limit Theorem states that when the sample size increases, the distribution of the sample means will approach the normal distribution.

Accepted Answer

A) True 
 B)False

Question 13

A manager wants to build 3-sigma control limits for a process. The target value for the mean of the process is 10 units, and the standard deviation of the process is 6. If samples of size 9 are to be taken, the UCL and LCL will be

Accepted Answer

A)  -8 and 28 
B)  16 and 4 
C)  12 and 8 
D)  4 and 16 
E)  8 and 12 
A)  -8 and 28 
B)  16 and 4 
C)  12 and 8 
D)  4 and 16 
E)  8 and 12

Question 14

The __________ are calculated to show how much allowance should be made for natural variation.

Accepted Answer

UCL and LC

Question 15

A process that is in statistical control will always yield products that meet their design specifications.

Accepted Answer

A) True 
 B)False

Question 16

The local newspaper receives several complaints per day about typographic errors. Over a seven-day period, the publisher has received calls from readers reporting the following number of errors: 4, 3, 2, 6, 7, 3, and 9. Based on these data alone, what type of control chart(s) should the publisher use?

Accepted Answer

A)  p-chart 
B)  c-chart 
C)  $\bar { X }$ -chart 
D)  R-chart 
E)  $\bar { X }$ - and R-charts 
A)  p-chart 
B)  c-chart 
C)  $\bar { X }$ -chart 
D)  R-chart 
E)  $\bar { X }$ - and R-charts

Question 17

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, the z-value = 1.96.
The

Question 18

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

Accepted Answer

A) True 
 B)False

Question 19

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 20

The __________ is the lowest level of quality that we are willing to accept.

Accepted Answer

AQL or acc

Exam 7: Statistical Process Control

Acceptance sampling is usually used to control

In most acceptance sampling plans, when a lot is rejected, the entire lot is inspected and all defective items are replaced. When using this technique the AOQ

The p-chart tells us whether there has been a

Mistakes stemming from workers' inadequate training represent an assignable cause of variation.

Larry's boat shop wants to monitor the number of blemishes in the paint of each boat. Construct a 3-sigma c-chart to determine if their paint process is in control using the following data. Sample Number Number of Defects 1 3 2 4 3 2 4 1 5 3 6 2 7 1 8 4 9 2 10 3

X-bar charts are used when we are sampling attributes.

To set Xˉ\bar { X }Xˉ -chart upper and lower control limits, one must know the process central line, which is the

Which of the following is true regarding the average outgoing quality level?

The Central Limit Theorem states that when the sample size increases, the distribution of the sample means will approach the normal distribution.

A manager wants to build 3-sigma control limits for a process. The target value for the mean of the process is 10 units, and the standard deviation of the process is 6. If samples of size 9 are to be taken, the UCL and LCL will be

The __________ are calculated to show how much allowance should be made for natural variation.

A process that is in statistical control will always yield products that meet their design specifications.

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

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

The __________ is the lowest level of quality that we are willing to accept.

Operations and Productivity

Operations Strategy in a Global Environment

Project Management

Forecasting

Design of Goods and Services

Managing Quality

Process Strategy

Capacity and Constraint Management

Location Strategies

Layout Strategies

Human Resources, Job Design, and Work Measurement

Supply-Chain Management

Outsourcing as a Supply-Chain Strategy

Inventory Management

Aggregate Planning

Material Requirements Planning MRP and ERP

Short-Term Scheduling

Just-In-Time and Lean Options

Maintenance and Reliability

Decision-Making Tools

Linear Programming

Transportation Models

Waiting-Line Models

Learning Curves

Simulation

Filters

To set $\bar { X }$ -chart upper and lower control limits, one must know the process central line, which is the