Test Bank Tools Acceptance Sampling Chapter 3

CHAPTER 3 SUPPLEMENT

OPERATIONAL DECISION-MAKING TOOLS: ACCEPTANCE SAMPLING

CHAPTER LEARNING OBJECTIVES

S1.Explain the process of a single sample attribute plan and the relationships of its associated measures. A single-sample attribute plan has as its basis an attribute that can be evaluated with a simple, discrete decision, such as defective or not defective or good or bad. The design of a sampling plan includes both the structural components and performance measures. These performance measures include the producer’s and consumer’s risks, the AQL, and the LTPD.

S2. Interpret an operating characteristic (OC) curve. The performance measures included in a sampling plan can be represented graphically with an OC curve. The OC curve measures the probability of accepting a lot for different quality (proportion defective) levels given a specific sample size (n) and acceptance level (c). Management can use such a graph to determine if their sampling plan meets the performance measures they have established.

S3. Interpret an average outgoing quality (AOQ) curve and explain the procedure followed when defective items are found in a lot. All lots, whether or not they are accepted, will pass on some defective items to the customer. AOQ is a measure of the expected number of defective items that will pass on to the customer with the sampling plan selected. When a lot is rejected as a result of the sampling plan, it is assumed that it will be subjected to a complete inspection, and all defective items will be replaced with good ones. Also, even when a lot is accepted, the defective items found in the sample will be replaced. Thus, some portion of all the defective items contained in all the lots produced will be replaced before they are passed on to the customer. The remaining defective items that make their way to the customer are contained in lots that are accepted.

S4. Discuss the rationale for choosing between single-, double-, and multiple-sampling plans. In a double-sampling plan, a small sample is taken first; if the quality is very good, the lot is accepted, and if the sample is very poor, the lot is rejected. However, if the initial sample is inconclusive, a second sample is taken and the lot is either accepted or rejected based on the combined results of the two samples. A multiple-sampling plan, also referred to as a sequential-sampling plan, generally employs the smallest sample size of any of the sampling plans we have discussed. Choosing among single-, double-, or multiple-sampling plans is an economic decision. When the cost of obtaining a sample is very high compared with the inspection cost, a single-sampling plan is preferred. Alternatively, if the cost of sampling is low relative to inspection costs, a double- or multiple-sampling plan may be preferred.

TRUE-FALSE STATEMENTS

1. Acceptance sampling is consistent with TQM’s philosophy of zero defects.

Difficulty: Easy

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

2. A sampling plan provides a set of guidelines for accepting a lot.

Difficulty: Easy

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

3. With acceptance sampling, a lot is either rejected or accepted depending on the number of defects found in a sample.

Difficulty: Medium

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

4. Six Sigma companies report defective parts per million (PPM) versus the more traditional defective parts per hundred.

Difficulty: Medium

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

5. The simplest form of a sampling plan is a single-sample attribute plan.

Difficulty: Easy

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

6. Acceptance sampling involves the inspection of a non-random sample of units selected from a lot.

Difficulty: Medium

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

7. Acceptance sampling is based on the premise that a lot contains some acceptable number of defective items.

Difficulty: Hard

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

8. With a single-sample attribute plan, only one of the items randomly sampled from a lot is inspected.

Difficulty: Medium

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

9. A lot is rejected if the number of defective units found in a random sample exceeds a predetermined acceptable number of defective units.

Difficulty: Medium

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

10. An operating characteristics (OC) curve is a graph that measures the probability of accepting a lot with no defective items.

Difficulty: Medium

Learning Objective: Interpret an operating characteristic (OC) curve.

Section Reference: S3.2 The Operating Characteristic Curve

11. The consumer’s risk is the probability of rejecting a lot that meets the acceptable quality level (AQL).

Difficulty: Medium

Learning Objective: Interpret an average outgoing quality (AOQ) curve and explain the procedure followed when defective items are found in a lot.

Section Reference: S3.3 Average Outgoing Quality

12. The consumer’s risk is the probability of accepting a lot in which the fraction of defective items exceeds the lot tolerance percent defective (LTPD).

Difficulty: Medium

Learning Objective: Interpret an average outgoing quality (AOQ) curve and explain the procedure followed when defective items are found in a lot.

Section Reference: S3.3 Average Outgoing Quality

13. The average outgoing quality (AOQ) is a measure of the expected number of defective items that will pass on to the customer with the sampling plan selected.

Difficulty: Medium

Learning Objective: Interpret an average outgoing quality (AOQ) curve and explain the procedure followed when defective items are found in a lot.

Section Reference: S3.3 Average Outgoing Quality

14. Double-sampling plans are often less costly than single-sampling plans.

Difficulty: Easy

Learning Objective: Discuss the rationale for choosing between single-, double-, and multiple-sampling plans.

Section Reference: S3.4 Double- and Multiple-Sampling Plans

15. A multiple-sampling plan uses the smallest sample size of any sampling plan.

Difficulty: Medium

Learning Objective: Discuss the rationale for choosing between single-, double-, and multiple-sampling plans.

Section Reference: S3.4 Double- and Multiple-Sampling Plans

16. A multiple-sampling plan uses the smallest sample size of any sampling plan.

Difficulty: Medium

Learning Objective: Discuss the rationale for choosing between single-, double-, and multiple-sampling plans.

Section Reference: S3.4 Double- and Multiple-Sampling Plans

17. Choosing among a single-, double- and multiple-sampling plans is a strategic versus an economic decision.

Difficulty: Medium

Learning Objective: Discuss the rationale for choosing between single-, double-, and multiple-sampling plans.

Section Reference: S3.4 Double- and Multiple-Sampling Plans

MULTIPLE CHOICE QUESTIONS

18. The probability of rejecting a lot that has an acceptable quality level is referred to as the

a) producer’s risk.

b) consumer’s risk.

c) lot tolerance percent defective.

d) acceptable quality level.

Difficulty: Easy

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

19. The probability of accepting a lot that has a higher percentage of defective items than the lot tolerance percent defective is referred to as the

a) producer’s risk.

b) sampling plan.

c) consumer’s risk.

d) average outgoing quality.

Difficulty: Easy

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

20. Six Sigma companies report

a) defective parts per million.

b) defective parts per thousand.

c) defective parts per hundred.

d) no defective parts.

Difficulty: Easy

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

21. Acceptance sampling is still used today for all the following reasons except

a) government regulations.

b) contractual requirements.

c) industry standards.

d) total quality management principles.

Difficulty: Medium

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

22. A(n) ___ curve is a graph showing the probability of accepting a lot for different quality levels with a specific sampling plan.

a) operating characteristic (OC)

b) average outgoing quality

c) lot tolerance percent defective

d) single-sample attribute

Difficulty: Medium

Learning Objective: Interpret an operating characteristic (OC) curve.

Section Reference: S3.2 The Operating Characteristic Curve

23. The consumer’s willingness to accept lots with a small proportion of defective items is known as the acceptable

a) sampling plan.

b) quality level.

c) consumer’s risk.

d) producer’s risk.

Difficulty: Easy

Learning Objective: Interpret an average outgoing quality (AOQ) curve and explain the procedure followed when defective items are found in a lot.

Section Reference: S3.3 Average Outgoing Quality

24. The ___ is the maximum number of defective items a customer will accept in a lot.

a) producer’s risk

b) consumer’s risk

c) average outgoing quality

d) lot tolerance percent defective

Difficulty: Medium

Learning Objective: Interpret an average outgoing quality (AOQ) curve and explain the procedure followed when defective items are found in a lot.

Section Reference: S3.3 Average Outgoing Quality

25. An operating characteristic (OC) curve is a graph that measures

a) the acceptable proportion of defects in a lot to the consumer.

b) the probability of accepting a lot for different quality levels with a specific sampling plan.

c) the probability of accepting a lot in which the fraction of defectives exceeds the lot tolerance percent defective.

d) the maximum number of defective items a consumer will accept in a lot.

Difficulty: Medium

Learning Objective: Interpret an average outgoing quality (AOQ) curve and explain the procedure followed when defective items are found in a lot.

Section Reference: S3.3 Average Outgoing Quality

26. The expected number of defective items that will pass on to the customer with a sampling plan is known as the

a) lot tolerance percent defective.

b) acceptable quality level.

c) average outgoing quality.

d) sampling plan.

Difficulty: Medium

Learning Objective: Interpret an average outgoing quality (AOQ) curve and explain the procedure followed when defective items are found in a lot.

Section Reference: S3.3 Average Outgoing Quality

SHORT-ANSWER ESSAY QUESTIONS

27. Is acceptance sampling consistent with TQM?

Difficulty: Medium

Learning Objective: Explain the process of a single-sample attribute plan and the relationships of its associated measures.

Section Reference: S3.1 Single-Sample Attribute Plan

28. What is the advantage of a multiple-sampling plan?

Difficulty: Medium

Learning Objective: Discuss the rationale for choosing between single-, double-, and multiple-sampling plans.

Section Reference: S3.4 Double- and Multiple-Sampling Plans

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