Question 1

Why do range charts exist? Aren't x-bar charts enough?

Accepted Answer

Range charts and mean charts perform dif

Question 2

Which of the following is true regarding the relationship between AOQ and the true population percent defective?

Accepted Answer

A)  AOQ is greater than the true percent defective. 
B)  AOQ is the same as the true percent defective. 
C)  AOQ is less than the true percent defective. 
D)  There is no relationship between AOQ and the true percent defective. 
E)  The relationship between these two cannot be determined. 
A)  AOQ is greater than the true percent defective. 
B)  AOQ is the same as the true percent defective. 
C)  AOQ is less than the true percent defective. 
D)  There is no relationship between AOQ and the true percent defective. 
E)  The relationship between these two cannot be determined.

Question 3

If the process average is in control, then the process range must also be in control.

Accepted Answer

A) True 
 B)False

Question 4

Cartons of Plaster of Paris are supposed to weigh exactly 32 oz. Inspectors want to develop process control charts. They take ten samples of six boxes each and weigh them. Based on the following data, compute the lower and upper control limits and determine whether the process is in control.
 $$\begin{array} { | c | c | c | } 
\hline \text { Sample } & \text { Mean } & \text { Range } \
\hline 1 & 33.8 & 1.1 \
\hline 2 & 34.6 & 0.3 \
\hline 3 & 34.7 & 0.4 \
\hline 4 & 34.1 & 0.7 \
\hline 5 & 34.2 & 0.3 \
\hline 6 & 34.3 & 0.4 \
\hline 7 & 33.9 & 0.5 \
\hline 8 & 34.1 & 0.8 \
\hline 9 & 34.2 & 0.4 \
\hline 10 & 34.4 & 0.3 \
\hline
\end{array}$$

Accepted Answer

n = 6; overall mean = 34.23; @#IMG-DLM& = 0.52.
 @#IMG-DLM&

Question 5

Which of the following is true of a p-chart?

Accepted Answer

A)  The lower control limit is found by subtracting a fraction from the average number of defects. 
B)  The lower control limit indicates the minimum acceptable number of defects. 
C)  The lower control limit equals D3 times p-bar. 
D)  The lower control limit may be at zero. 
E)  The lower control limit is the same as the lot tolerance percent defective. 
A)  The lower control limit is found by subtracting a fraction from the average number of defects. 
B)  The lower control limit indicates the minimum acceptable number of defects. 
C)  The lower control limit equals D3 times p-bar. 
D)  The lower control limit may be at zero. 
E)  The lower control limit is the same as the lot tolerance percent defective.

Question 6

The specifications for a manifold gasket that installs between two engine parts calls for a thickness of 2.500 mm ± .020 mm. The standard deviation of the process is estimated to be 0.004 mm. What are the upper and lower specification limits for this product? The process is currently operating at a mean thickness of 2.50 mm. (a) What is the Cp for this process? (b) About what percent of all units of this liner will meet specifications? Does this meet the technical definition of Six Sigma?

Accepted Answer

(a) LSL = 2.48 mm., USL = 2.52 mm. C_p = (

Question 7

The ________ is the chief way to control attributes.

Accepted Answer

The answer of The ________ is the chief way to...

Question 8

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

@#IMG-DLM& @#IMG-DLM& The proc

Question 9

A Cpk index greater than ________ is a capable process, one that generates fewer than 2.7 defects per 1000 at the ±3σ level.

Accepted Answer

Question 10

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

Accepted Answer

AQL or acc

Question 11

Control charts for variables are based on data that come from

Accepted Answer

A)  acceptance sampling. 
B)  individual items. 
C)  averages of small samples. 
D)  averages of large samples. 
E)  the entire lot. 
A)  acceptance sampling. 
B)  individual items. 
C)  averages of small samples. 
D)  averages of large samples. 
E)  the entire lot.

Question 12

Natural variations

Accepted Answer

A)  affect almost every production process. 
B)  are the many sources of variation that occur when a process is under control. 
C)  when grouped, form a pattern, or distribution. 
D)  are tolerated, within limits, when a process is under control. 
E)  All of the above are true. 
A)  affect almost every production process. 
B)  are the many sources of variation that occur when a process is under control. 
C)  when grouped, form a pattern, or distribution. 
D)  are tolerated, within limits, when a process is under control. 
E)  All of the above are true.

Question 13

A hospital-billing auditor has been inspecting patient bills. While almost all bills contain some errors, the auditor is looking now for large errors (errors in excess of $250). Among the last 100 bills inspected, the defect rate has been 16%. Calculate the upper and lower limits for the billing process for 99.7% confidence.

Accepted Answer

0.16 plus

Question 14

The ________ is a quality control chart that indicates when changes occur in the central tendency of a production process.

Accepted Answer

The answer of The ________ is a quality control chart...

Question 15

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)  the number of outgoing units. 
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)  the number of outgoing units.

Question 16

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 17

An acceptance sampling plan's ability to discriminate between low quality lots and high quality lots is described by

Accepted Answer

A)  a Gantt chart. 
B)  the Central Limit Theorem. 
C)  a process control chart. 
D)  an operating characteristics curve. 
E)  a range chart. 
A)  a Gantt chart. 
B)  the Central Limit Theorem. 
C)  a process control chart. 
D)  an operating characteristics curve. 
E)  a range chart.

Question 18

The usual purpose of an R-chart is to signal 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)  change in sample size. 
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)  change in sample size.

Question 19

Red Top Cab Company receives multiple complaints per day about driver behavior. Over 9 days the owner recorded the number of calls to be 3, 0, 8, 9, 6, 7, 4, 9, 8. What is the upper control limit for the c-chart?

Accepted Answer

A)  13.35 
B)  8.45 
C)  24.00 
D)  0.00 
E)  9.03 
A)  13.35 
B)  8.45 
C)  24.00 
D)  0.00 
E)  9.03

Question 20

________ is a method of measuring samples of lots or batches of product against predetermined standards.

Accepted Answer

The answer of ________ is a method of measuring samples...

Exam 26: Statistical Process Control

Why do range charts exist? Aren't x-bar charts enough?

Which of the following is true regarding the relationship between AOQ and the true population percent defective?

If the process average is in control, then the process range must also be in control.

Which of the following is true of a p-chart?

The ________ is the chief way to control attributes.

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

A Cpk index greater than ________ is a capable process, one that generates fewer than 2.7 defects per 1000 at the ±3σ level.

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

Control charts for variables are based on data that come from

Natural variations

The ________ is a quality control chart that indicates when changes occur in the central tendency of a production process.

Acceptance sampling is usually used to control

The p-chart tells us whether there has been a

An acceptance sampling plan's ability to discriminate between low quality lots and high quality lots is described by

The usual purpose of an R-chart is to signal whether there has been a

Red Top Cab Company receives multiple complaints per day about driver behavior. Over 9 days the owner recorded the number of calls to be 3, 0, 8, 9, 6, 7, 4, 9, 8. What is the upper control limit for the c-chart?

________ is a method of measuring samples of lots or batches of product against predetermined standards.

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_pk index greater than ________ is a capable process, one that generates fewer than 2.7 defects per 1000 at the ±3σ level.