Deck 23: Acceptance Sampling Plans

Question 1

A double-sampling plan is usually less expensive than a single-sampling plan if the lot has a low number of defectives.

Answer 1

True

Question 2

The lot tolerance proportion defective (LTPD)is the customer's desired level of quality.

Answer 2

False

Question 3

As more firms initiate total quality management systems,the need for acceptance sampling will increase.

Answer 3

False

Question 4

Acceptance sampling is an inspection procedure used to determine whether to accept or reject a specific quantity of material.

Question 5

Lot tolerance proportion defective (LTPD)can be defined as the:

A)quality level desired by the consumer.
B)worst quality level the consumer can tolerate.
C)probability of rejecting a good lot (i.e. ,when a lot is,in fact,acceptable to the consumer).
D)probability of accepting a bad lot (i.e. ,when a lot is,in fact,not acceptable to the consumer).

Question 6

A single-sampling plan has n = 200 and c = 6.A sample is taken and five items are found to be defective.What should be done?

A)Another sample should be taken.
B)The lot should be rejected.
C)The lot should be accepted.
D)The five items should be repaired,and then the entire lot should be accepted.

Question 7

A double-sampling plan has n1 = 50,n2 = 100,c1 = 2,and c2 = 4.Suppose on the first sample,one defective item was discovered.What should be done?

A)Reject the entire lot.
B)Take a second sample of 100 units.
C)Accept the entire lot.
D)Repair the defective units,and accept the entire lot.

Question 8

Acceptable quality level can be defined as the:

A)quality level desired by the consumer.
B)worst quality level the consumer can tolerate.
C)probability of rejecting a good lot (i.e. ,when a lot is,in fact,acceptable to the consumer).
D)probability of accepting a bad lot (i.e. ,when a lot is,in fact,not acceptable to the consumer).

Question 9

Which of the following is an example of a type I error?

A)buying a carton of eggs at the store and discovering that one was broken
B)releasing a guilty defendant
C)returning your computer for warranty repair when the fault was caused by user error
D)passing defective materials from a supplier into your processes to keep your workers busy

Question 10

A sequential sampling plan generally lowers the ANI.

Question 11

The AOQL is the highest point in the plot of AOQ against the percentage of defectives in the lot.

Question 12

Increasing c while holding n constant decreases the producer's risk and increases the consumer's risk.

Question 13

Which of the following is an example of a type II error?

A)convicting an innocent defendant
B)returning your "dead" stereo for warranty repair when its malfunction was caused by it not being plugged in
C)halting production to adjust a machine when your process was actually in control
D)eating food that has spoiled

Question 14

If the sample size is increased and the acceptance level is unchanged,the OC curve will have a higher consumer's risk.

Question 15

An operating characteristic curve is a plot of the probability of accepting the lot against the proportion defectives.

Question 16

A double-sampling plan is usually less expensive than a single-sampling plan if the lot has a high number of defectives.

Question 17

Rectified inspection occurs when all defective items in the lot are replaced with good items if the lot is rejected and any defective items in the samples are replaced if the lot is accepted.

Question 18

A double-sampling plan requires two sample sizes and two acceptance numbers.

Question 19

The distance between 1.0 and where the AQL intersects the OC curve is the value â (Beta).

Question 20

If the sample size is increased and the acceptance level is unchanged,the OC curve will have a slope that is more negative.

Question 21

Which one of the following alternatives will reduce the producer's risk for a given AQL and LTPD?

A)Reduce n and keep c constant.
B)Increase n and keep c constant.
C)Increase n and reduce c.
D)Increase alpha.

Question 22

Which one of the following actions will decrease the producer's risk?

A)Increase n and keep c constant.
B)Decrease n and keep c constant.
C)Keep n constant and decrease c.
D)Increase n and decrease c.

Question 23

A quality manager has established a sampling plan that calls for a sample size of 75 units and an acceptance number of 2.The supplier has agreed to a contract that calls for an AQL of 0.02 and an LTPD of .04.What is the AOQL? Table G.1 is appended to this exam.

A)less than 0.11
B)between 0.11 and 0.14
C)between 0.14 and 0.17
D)greater than 0.17

Question 24

A quality manager has established a sampling plan that calls for a sample size of 50 units and an acceptance number of 1 The supplier has agreed to a contract that calls for an AQL of 0.02 and an LTPD of .07.What is the consumer's risk? Table G.1 is appended to this exam.

A)less than 0.08
B)between 0.08 and 0.10
C)between 0.10 and 0.12
D)greater than 0.12

Question 25

A quality manager has established a sampling plan that calls for a sample size of 75 units and an acceptance number of 2.The supplier has agreed to a contract that calls for an AQL of 0.02 and an LTPD of .04.What is the probability of accepting the lot if the actual percentage of defective is 3%? Table G.1 is appended to this exam.

A)less than 0.63
B)between 0.63 and 0.66
C)between 0.66 and 0.69
D)greater than 0.69

Question 26

A double-sampling plan has n1 = 50,n2 = 100,c1 = 2,and c2 = 4.Suppose the first sample revealed two defectives.What should be done?

A)Reject the entire lot.
B)Take a second sampling of 100 units.
C)Accept the entire lot.
D)Repeat the tests on the first sample.

Question 27

A quality manager has established a sampling plan that calls for a sample size of 50 units and an acceptance number of 2.The supplier has agreed to a contract that calls for an AQL of 0.02 and an LTPD of .07.What is the producer's risk? Table G.1 is appended to this exam.

A)less than 0.07
B)between 0.07 and 0.09
C)between 0.09 and 0.11
D)greater than 0.11

Question 28

A double-sampling plan has n1 = 50,n2 = 100,c1 = 2,and c2 = 4.Suppose on the first sample,five defectives were discovered.How many total items will be inspected before a decision is reached?

A)50
B)100
C)150
D)This cannot be determined with the information provided.

Question 29

Which one of the following will increase the consumer's risk?

A)Decrease sample size and hold constant the number of defective items in a sample.
B)Decrease the acceptable number of defective items in a sample and hold constant the sample size.
C)Increase the sample size and decrease the acceptable number of defective items in a sample.
D)Decrease the acceptable quality level and hold constant both sample size and the acceptable number of defective items in a sample.

Question 30

A single-sampling plan by attributes is needed for a purchased component.Given the following information,what is the consumer's risk? Table G.1 is appended to this exam. Sample size = 50
Acceptance number (c)= 3
Acceptance quality level (AQL )= 0.01
Lot tolerance proportion defective (LTPD)= 0.04

A)greater than or equal to 0 but less than or equal to 0.25
B)greater than 0.25 but less than or equal to 0.50
C)greater than 0.50 but less than or equal to 0.75
D)greater than 0.75 but less than or equal to 1.00

Question 31

The quality manager has fixed n = 20 and c = 2 for a single-attribute sampling plan.Given AQL = 0.01 and LTPD = 0.05,what is the producer's risk? Table G.1 is appended to this exam.

A)between 0.0001 and 0.01
B)between 0.01 and 0.1
C)between 0.99 and 0.9999
D)between 0.9 and 0.99

Question 32

A quality manager has established a sampling plan that calls for a sample size of 75 units and an acceptance number of 2.The supplier has agreed to a contract that calls for an AQL of 0.02 and an LTPD of .04.What is the consumer's risk? Table G.1 is appended to this exam.

A)less than 0.40
B)between 0.40 and 0.44
C)between 0.44 and 0.48
D)greater than 0.48

Question 33

The management of a company wishes to develop a new acceptance sampling plan that keeps acceptable quality level,lot tolerance proportion defective,and c constant.If the sample size (n)is increased,compared to the prior plan,which of the following is TRUE?

A)α increases
B)α decreases
C)β increases
D)α and β increase

Question 34

A quality manager has established a sampling plan that calls for a sample size of 75 units and an acceptance number of 2.The supplier has agreed to a contract that calls for an AQL of 0.02 and an LTPD of .04.What is the producer's risk? Table G.1 is appended to this exam.

A)less than 0.16
B)between 0.16 and 0.18
C)between 0.18 and 0.2
D)greater than 0.2

Question 35

Which of the following statements is TRUE?

A)Sequential-sampling plans are preferred to single-sampling plans because the average number of items inspected is generally lower.
B)With a sequential-sampling plan,each time an item is inspected,a decision is made to accept or reject a lot.
C)With a sequential-sampling plan,sampling continues until the lot is rejected.
D)Sequential-sampling plans are defined by four parameters: n1,n2,c1,c2.

Question 36

Which one of the following alternatives will reduce the consumer's risk for a given AQL and LTPD?

A)Reduce n and keep c constant.
B)Increase n and keep c constant.
C)Reduce n and increase c.
D)Increase beta.

Question 37

A quality manager has established a sampling plan that calls for a sample size of 75 units from a shipment of 5000 pieces and an acceptance number of 2.The supplier has agreed to a contract that calls for an AQL of 0.02 and an LTPD of .04.What is the AOQ if the actual percentage of defectives in the lot is 2%? Table G.1 is appended to this exam.

A)less than 0.014
B)between 0.014 and 0.018
C)between 0.018 and 0.022
D)greater than 0.022

Question 38

For a given AQL and LTPD,which one of the following statements about the single-sampling plan is TRUE?

A)If c stays constant but n is increased,both the producer's risk and the consumer's risk will increase.
B)If c stays constant but n is increased,both the producer's risk and the consumer's risk will decrease.
C)If n stays constant but c is increased,the producer's risk will decrease and the consumer's risk will increase.
D)If n stays constant but c is increased,the producer's risk will increase and the consumer's risk will decrease.

Question 39

An item is purchased with one surface polished to a specified finish quality.From each incoming shipment,a sample of items is randomly selected and the polished surface of each sample item is compared with a standard and judged to be either acceptable or unacceptable.The following parameters have been established: AQL = 0.02,= 0.05,LTPD = 0.09,and = 0.10.Table G.1 is appended to this exam.What are the sample size and the acceptance number?

A)n = 89,c = 4
B)n = 39,c = 1
C)n = 43,c = 1
D)n = 237,c = 15

Question 40

The average outgoing quality (AOQ)is:

A)the average number of good units produced per hour.
B)the expected proportion of defects a sampling plan will allow.
C)the level of quality desired by the customer.
D)the worst level of quality tolerated by the consumer.

Question 41

A lot of 2,000 items has just arrived.A single sampling calls for a sample size of 100 and c = 3.What is the average outgoing quality limit,assuming that all defectives in the entire lot are replaced if it is rejected and all defectives are replaced in the sample if it is accepted? Table G.1 is appended to this exam.

A)less than or equal to 0.0150
B)greater than 0.0150 but less than or equal to 0.0175
C)greater than 0.0175 but less than or equal to 0.0200
D)greater than 0.0200

Question 42

Use Table G.1 for the following question.What is the acceptance number of a single-sampling plan if n = 300,LPTD = 0.02,and = 0.15?

A)c = 0
B)c = 1
C)c = 2
D)c = 3

Question 43

Use Table G.1 for the following question.What is the acceptance number of a single-sampling plan if n = 400,AQL = 0.002,and α= 0.01?

A)c = 0
B)c = 1
C)c = 2
D)c = 3

Question 44

The average outgoing quality (AOQ)is the:

A)proportion of defectives that the sampling plan will allow to pass.
B)proportion of non-defectives that the sampling plan will allow to pass.
C)highest proportion of defectives that the sampling plan will allow to pass.
D)lowest proportion of defectives that the sampling plan will allow to pass.

Question 45

A single-sampling plan has the following performance: What is the average outgoing quality limit if the sample size is 200 and the lot size is 6,000?

A)less than or equal to 0.0200
B)greater than 0.0200 but less than or equal to 0.0220
C)greater than 0.0220 but less than or equal to 0.0230
D)greater than 0.0230

Question 46

A sample of 100 items is randomly selected from a shipment of incoming materials.AQL and LTPD have been established at 0.01 and 0.07,respectively.When four or more defective items are found in a sample,the shipment is rejected.What is the value of α? Table G.1 is appended to this exam.

A)less than or equal to 0.04
B)greater than 0.04 but less than or equal to 0.06
C)greater than 0.06 but less than or equal to 0.08
D)greater than 0.08

Question 47

A quality manager has established a sampling plan that calls for a sample size of 200 units and an acceptance number of 3.The supplier has agreed to a contract that calls for an AQL of 0.01 and an LTPD of .03.What is the consumer's risk? Table G.1 is appended to this exam.

A)less than 0.14
B)between 0.14 and 0.15
C)between 0.15 and 0.16
D)greater than 0.16

Question 48

This OC curve represents a sampling plan developed for a lot size of 1000,a sample size of 15,and an acceptance number of 2.The probability of acceptance for each of the first six points appears next to the plotted point.What is the average outgoing quality for an incoming fraction defective of 0.25?

A)less than 0.045
B)greater than or equal to 0.045 but less than 0.055
C)greater than or equal to 0.055 but less than 0.065
D)greater than or equal to 0.065

Question 49

This OC curve represents a sampling plan developed for a lot size of 500,a sample size of 15,and an acceptance number of 2.The probability of acceptance for each of the first six points appears next to the plotted point.What is the average outgoing quality for an incoming fraction defective of 0.15?

A)less than 0.06
B)greater than or equal to 0.06 but less than 0.07
C)greater than or equal to 0.07 but less than 0.08
D)greater than or equal to 0.08

Question 50

This OC curve represents a sampling plan developed for a lot size of 500,a sample size of 15,and an acceptance number of 2.The probability of acceptance for each of the first six points appears next to the plotted point.What is the average outgoing quality limit?

A)less than 0.08
B)greater than or equal to 0.08 but less than 0.09
C)greater than or equal to 0.09 but less than 0.10
D)greater than or equal to 0.10

Question 51

A sample of 100 items is randomly selected from a shipment of incoming materials.AQL and LTPD have been established at 0.01 and 0.07,respectively.When four or more defective items are found in a sample,the shipment is rejected.What is the value of β? Table G.1 is appended to this exam.

A)less than or equal to 0.05
B)greater than 0.05 but less than or equal to 0.10
C)greater than 0.10 but less than or equal to 0.15
D)greater than 0.15

Question 52

A lot of 1,000 items is on the loading dock.A single-sampling plan calls for a sample size of 10.The following table gives the probability of acceptance for the plan over a range of possible quality levels. What is the average outgoing quality limit for this plan?

A)less than or equal to 0.018
B)greater than 0.0180 but less than or equal to 0.0200
C)greater than 0.0200 but less than or equal to 0.0220
D)greater than 0.0220

Question 53

A single-sampling plan using a sample size of 50 on a lot size of 2,000 has the following performance: Today the company making the purchase receives two lots of 2,000 items and the inspection department is in a big hurry.Which action will result in an identical AOQL for the purchasing company?

A)Take a random sample of 25 from each lot and accept or reject both lots based on the results.
B)Take a random sample of 50 from one lot and accept or reject the second lot based on the first lot's results.
C)Take a random sample of 100 from one lot and accept or reject the second lot based on the first lot's results.
D)Take a random sample of 50 from each lot and accept or reject each lot based on the results.

Question 54

A company wants to develop an acceptance sampling plan that keeps the producer's risk at 0.03 or less and the customer's risk at 0.10 or less.The acceptable quality level (AQL)is 0.01,and the lot tolerance proportion defective (LTPD)has been set at 0.10.Which one of the following plans gives us the desired protection? Table G.1 is appended to this exam.

A)c = 3,n = 190
B)c = 2,n = 54
C)c = 1,n = 30
D)c = 1,n = 20

Question 55

A company is developing an acceptance sampling plan to monitor quality.The acceptable quality level (AQL)is 0.01,and a sampling plan having c = 5 is being considered.If a producer's risk of 0.03 is desired,what should be the sample size? Table G.1 is appended to this exam.

A)less than or equal to 25
B)more than 25 but less than or equal to 175
C)more than 175 but less than or equal to 325
D)more than 325

Question 56

A quality manager has established a sampling plan that calls for a sample size of 100 units and an acceptance number of 2.The supplier has agreed to a contract that calls for an AQL of 0.01 and an LTPD of .05.Which of the following statements is TRUE? Table G.1 is appended to this exam.

A)Lowering the acceptance number to 1 will raise the probability of a type II error.
B)Increasing the sample size will increase α.
C)Raising the AQL to 0.02 will lower the chance of a type I error.
D)Reducing the LTPD to 0.04 will reduce the chance of a type II error.

Question 57

This OC curve represents a sampling plan developed for a lot size of 1000,a sample size of 15,and an acceptance number of 2.The probability of acceptance for each of the first six points appears next to the plotted point.What incoming fraction defective is associated with the average outgoing quality limit?

A)0.10
B)0.15
C)0.20
D)0.25

Question 58

A rectified inspection plan requires that:

A)a rejected lot be returned to the supplier.
B)a rejected lot be subjected to 100% inspection.
C)a sample with too many defectives be returned to the lot for mixing and resampling.
D)all units in the sample be returned to the lot if it is rejected.

Question 59

A quality manager has established a sampling plan that calls for a sample size of 200 units and an acceptance number of 3.The supplier has agreed to a contract that calls for an AQL of 0.01 and an LTPD of .03.What is the producer's risk? Table G.1 is appended to this exam.

A)more than 0.14
B)between 0.14 and 0.12
C)between 0.12 and 0.10
D)less than 0.10

Question 60

A manufacturer wants a sampling plan in which AQL = 0.02,LPTD = 0.12,α = 0.05,and β = 0.10.Which of the following values for n and c best satisfy these specifications? Table G.1 is appended to this exam.

A)n = 54,c = 3
B)n = 100,c = 2
C)n = 200,c = 1
D)n = 162,c = 0

Question 61

What is the basic idea of incoming inspection? Why does a producer perform it?

Question 62

A double-sampling plan has a lower ________ than a single-sampling plan.

Question 63

Discuss the two incorrect conclusions that can be made when using acceptance sampling.

Question 64

An ideal OC curve is shaped like a ________.

Question 65

If you were interested in minimizing the average number of items inspected,which type of sampling plan would you choose? Why?

Question 66

________ is an inspection procedure used to determine whether to accept or reject a specific quantity of material.

Question 67

________ is the risk that a lot with LTPD will be accepted-a type II error.

Question 68

Describe the process of a single-sampling plan.

Question 69

Champion Cooling Company has developed a sampling plan calling for a sample size of 25 and an acceptance number of 1.The proportion defective and probability of acceptance appear in the table.Floyd Electric,their supplier ships whatever Champion Cooling asks;sometimes the lot size is as small as 30 units and it has been as large as 10,000 units.Champion Cooling decides to stick with what they know,a sample size of 25 and an acceptance number of 1 despite advice to the contrary.Which statement regarding their sampling plan is best?

A)The average outgoing quality level will remain constant since the sample size and the acceptance number do not change.
B)The average outgoing quality level will vary as the lot size varies,but the average outgoing quality limit will remain constant.
C)The incoming fraction defective that produces the average outgoing quality limit will remain the same regardless of lot size.
D)The incoming fraction defective that produces the average outgoing quality limit will vary as the lot size varies.

Question 70

Discuss producer's risk and consumer's risk.

Question 71

Replacing all defective items in a rejected lot and all defective items in a sample with good items is called ________ inspection.

Question 72

________ is the risk that the sampling plan will fail to verify an acceptable lot's quality and thus reject it-a type I error.

Question 73

In general,a sequential sampling strategy will require a lower number of items be inspected if the actual percentage of defectives in the lot is ________.

Question 74

A small ________ can be disregarded in AOQ calculations involving an extremely large lot size.

Question 75

A graph that demonstrates how well a sampling plan distinguishes between shipments that should be accepted and shipments that should be rejected is a(n)________.

Question 76

The maximum value of the average outgoing quality over all possible values of the proportion defective is called the ________.

Question 77

A(n)________ is when the consumer randomly selects items from the lot and inspects them one by one.

Question 78

________ is the worst level of quality that the customer can tolerate.

Question 79

________ is the quality level desired by the consumer.

Question 80

Increasing c while holding n constant decreases the ________ risk and increases the ________ risk.