Question 1

If the process is known to have a mean of 15 and a standard deviation of 3, what are the three sigma upper and lower control limits for an x-bar chart?

Accepted Answer

@#IMG-DLM& Lower lim

Question 2

The number of runs up and down is:

Accepted Answer

A) 2 
B) 3 
C) 4 
D) 5 
E) none of these 
A) 2 
B) 3 
C) 4 
D) 5 
E) none of these

Question 3

Statistical process control focuses on the acceptability of process output.

Accepted Answer

A) True 
 B)False

Question 4

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 5

A plot below the lower control limit on the range chart: (I) should be ignored since lower variation is desirable
(II) may be an indication that process variation has decreased
(III) should be investigated for assignable cause

Accepted Answer

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

Question 6

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

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

Accepted Answer

A) True 
 B)False

Question 8

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

Accepted Answer

A) True 
 B)False

Question 9

What is the mean of the sampling distribution of sample means when service life is in control?

Accepted Answer

A) 250 hours 
B) 470 hours 
C) 495 hours 
D) 500 hours 
E) 515 hours 
A) 250 hours 
B) 470 hours 
C) 495 hours 
D) 500 hours 
E) 515 hours

Question 10

A c-chart is used for:

Accepted Answer

A) means 
B) ranges 
C) percent defective 
D) fraction defective per unit 
E) number of defects per unit 
A) means 
B) ranges 
C) percent defective 
D) fraction defective per unit 
E) number of defects per unit

Question 11

The greater the capability ratio, the higher the rejects.

Accepted Answer

A) True 
 B)False

Question 12

Run tests are useful in helping to identify nonrandom variations in a process.

Accepted Answer

A) True 
 B)False

Question 13

If the process is known to produce 11 percent defectives on average, what are the upper and lower control limits for an alpha risk of .10? .05? .01?

Accepted Answer

.1357 and

Question 14

A time-ordered plot of representative sample statistics is called a:

Accepted Answer

A) Gantt chart 
B) SIMO-chart 
C) Control Chart 
D) Up-Down Matrix 
E) Standard deviation table 
A) Gantt chart 
B) SIMO-chart 
C) Control Chart 
D) Up-Down Matrix 
E) Standard deviation table

Question 15

The optimum level of inspection is where the:

Accepted Answer

A) cost of inspection is minimum 
B) cost of passing defectives is minimum 
C) total cost of inspection and defectives is maximum 
D) total cost of inspection and defectives is minimum 
E) difference between inspection and defectives costs is minimum 
A) cost of inspection is minimum 
B) cost of passing defectives is minimum 
C) total cost of inspection and defectives is maximum 
D) total cost of inspection and defectives is minimum 
E) difference between inspection and defectives costs is minimum

Question 16

The basis for a statistical process control chart is a(the) __________.

Accepted Answer

A) process capability 
B) sampling distribution 
C) control limit 
D) sample range 
E) sample mean 
A) process capability 
B) sampling distribution 
C) control limit 
D) sample range 
E) sample mean

Question 17

"Process capability" compares "process variability" to the "tolerances."

Accepted Answer

A) True 
 B)False

Question 18

If the process is known to have a mean of 15 and a standard deviation of 3, what is the mean of the sampling distribution of sample means for whenever this process is under control? The standard deviation?

Accepted Answer

The answer of If the process is known to have...

Question 19

Non-random variation is likely whenever all observations are between the LCL and UCL.

Accepted Answer

A) True 
 B)False

Question 20

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

Exam 10: Quality Control

If the process is known to have a mean of 15 and a standard deviation of 3, what are the three sigma upper and lower control limits for an x-bar chart?

The number of runs up and down is:

Statistical process control focuses on the acceptability of process output.

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

A plot below the lower control limit on the range chart: (I) should be ignored since lower variation is desirable (II) may be an indication that process variation has decreased (III) should be investigated for assignable cause

What are the x-bar chart three sigma upper and lower control limits?

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

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

What is the mean of the sampling distribution of sample means when service life is in control?

A c-chart is used for:

The greater the capability ratio, the higher the rejects.

Run tests are useful in helping to identify nonrandom variations in a process.

If the process is known to produce 11 percent defectives on average, what are the upper and lower control limits for an alpha risk of .10? .05? .01?

A time-ordered plot of representative sample statistics is called a:

The optimum level of inspection is where the:

The basis for a statistical process control chart is a(the) __________.

"Process capability" compares "process variability" to the "tolerances."

If the process is known to have a mean of 15 and a standard deviation of 3, what is the mean of the sampling distribution of sample means for whenever this process is under control? The standard deviation?

Non-random variation is likely whenever all observations are between the LCL and UCL.

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?

Introduction to Operations Management

Competitiveness, Strategy, and Productivity

Forecasting

Product and Service Design

Strategic Capacity Planning for Products and Services

Process Selection and Facility Layout

Work Design and Measurement

Location Planning and Analysis

Management of Quality

Aggregate Planning and Master Scheduling

MRP and ERP

Inventory Management

Jit and Lean Operations

Supply Chain Management

Scheduling

Project Management

Management of Waiting Lines

Linear Programming

Extension 4: Reliability

Extension 5: Decision Theory

Extension 7: Learning Curves

Extension 8: The Transportation Model

Extension 10: Acceptance Sampling

Extension 14: Maintenance

Filters