Question 1

Sampling plans are designed considering both the cost and time required for the inspection.

Accepted Answer

Sampling plans aim to strike a balance between the cost and time required for inspection while ensuring a statistically valid sample size.

Question 2

In a single-sampling plan, the entire lot, or batch of items, is accepted or rejected based upon only one specified sized sample.

Accepted Answer

In a single-sampling plan, the acceptance or rejection decision is based on only one specified sized sample of the entire lot.

Question 3

Flexible acceptance sampling revises the sampling plan in response to actual results.

Accepted Answer

False

Question 4

Acceptance sampling is a form of inspection applied to items during an ongoing process.

Accepted Answer

Acceptance sampling is typically used to determine whether to accept or reject a batch of products after the production process, not during it.

Question 5

Acceptance sampling procedures can be applied to both attribute and variables inspection.

Accepted Answer

Acceptance sampling procedures can be applied to both attribute and variables inspection. In attribute sampling, the inspector inspects a sample of products to determine whether the product meets or fails to meet a predetermined set of standards or specifications. In variables sampling, the inspector measures a sample of products to determine how well they meet the specifications or criteria.

Question 6

Acceptance sampling procedures are applicable for inspection both before and after production.

Accepted Answer

Acceptance sampling procedures can be used for inspection before production to assess the quality of raw materials or components, as well as after production to ensure finished products meet pre-determined specifications.

Question 7

When is the average outgoing quality level (AOQL) at its peak?
A) when the incoming fraction defective is at a minimum
B) when the incoming fraction defective is at a maximum
C) when the outgoing fraction defective is at a minimum
D) when the outgoing fraction defective is constant
E) when the outgoing fraction defective begins to increase

Accepted Answer

The AOQL is at its peak when the incoming fraction defective is at a maximum because it represents the worst-case scenario for the quality level after inspection and rejection of defective items.

Question 8

Acceptance sampling is most useful when the cost consequences of passing defectives are low.

Accepted Answer

Acceptance sampling is most useful when the cost consequences of passing defectives are low because it allows for a less stringent inspection process, which can save time and money.

Question 9

The purpose of acceptance sampling is to decide whether a batch of items satisfies pre-determined standards.

Accepted Answer

Acceptance sampling involves taking a sample from a batch of items to determine whether the batch meets pre-determined standards or specifications. If the sample meets the criteria, the entire batch is accepted; if it does not, the entire batch is rejected. Therefore, the purpose of acceptance sampling is to decide whether a batch of items satisfies pre-determined standards.

Question 10

Acceptance sampling is applied to batches of items during the production process.

Accepted Answer

The answer of Acceptance sampling is applied to batches of...

Question 11

In a double-sampling plan, a second sample is taken if the results of the first sample are inconclusive.

Accepted Answer

In a double-sampling plan, a second sample is taken if the results of the first sample are inconclusive. Therefore, the given statement is true.

Question 12

A good sampling plan will occasionally reject a lot with very good quality.

Accepted Answer

This is because a good sampling plan involves randomly selecting a portion of the lot to inspect, which means there is always a chance that a high-quality portion of the lot may be missed in the sampling process.

Question 13

A double-sampling plan requires a second sample of exactly twice the size of the first sample.

Accepted Answer

In double-sampling plan, the second sample size is not necessarily twice the size of the first sample. It can be any size that is determined based on the results of the first sample.

Question 14

A graphical representation that shows the risk of: (1) accepting bad lots and (2) rejecting good lots is called the:
A) indifference curve.
B) operating characteristic curvE.
C) sampling plan.
D) inspection curve.
E) operating inspection plan.

Accepted Answer

The graphical representation that shows the risk of accepting bad lots and rejecting good lots is called the operating characteristic curve (OC curve). It is a plot of the probability of accepting a lot versus the fraction of nonconforming items in the lot, for a particular sampling plan. The OC curve helps managers to choose an appropriate sampling plan by balancing the risks of accepting bad lots and rejecting good lots. The other options (A, C, D, and E) are related to quality control and sampling plans but do not specifically refer to the graphical representation of risk associated with accepting or rejecting lots.

Question 15

Suppose that only two incoming fraction defective levels, 4 percent and 8 percent, are possible. These incoming fraction defective levels are equally likely. At a 4 percent incoming fraction defective, there's a 60 percent chance that a lot will be accepted. At 8 percent incoming fraction defective, there's a 20 percent chance that a lot will be accepted. Lots that are not accepted are subject to 100 percent sorting. What is average outgoing quality?
A) 40 percent
B) 20 percent
C) 10 percent
D) 4 percent
E) 2 percent

Accepted Answer

The average outgoing quality (AOQ) is calculated by considering the probability of acceptance and the defect rate for each incoming quality level. For 4% defect rate, the AOQ is 0.04 * 0.6 = 0.024. For 8% defect rate, the AOQ is 0.08 * 0.2 = 0.016. Since both levels are equally likely, the average AOQ is (0.024 + 0.016) / 2 = 0.02 or 2 percent.

Question 16

Acceptance sampling plans must specify the lot size, the sample size, and the acceptance/rejection criteria.

Accepted Answer

Acceptance sampling plans require specification of lot size, sample size, and acceptance/rejection criteria to evaluate the quality of a product or service by means of random sampling.

Question 17

The ability of an acceptance sampling plan to discriminate between good and bad lots is described by its operating characteristic curve.

Accepted Answer

The operating characteristic curve (OC curve) is a graph that illustrates the probability of accepting a lot with a certain level of quality, given a specific acceptance sampling plan. It shows how well the sampling plan can discriminate between good and bad lots based on the chosen acceptance and rejection criteria. Therefore, option A is true.

Question 18

Which of the following is associated with producer's risk?
A) LTPD
B) AQL
C) AOQL
D) SPC
E) Cpk

Accepted Answer

The answer of Which of the following is associated with...

Question 19

Which of the following is associated with consumer's risk?
A) LTPD
B) AQL
C) AOQL
D) SPC
E) Cpk

Accepted Answer

LTPD (Lot Tolerance Percent Defective) is a measure of the maximum percentage of defective items that a consumer is willing to tolerate in a product. It is associated with consumer's risk as it refers to the level of quality that a consumer is willing to accept, and any defects beyond this level can lead to dissatisfaction or harm. AQL (Acceptable Quality Level) and AOQL (Average Outgoing Quality Level) are measures mainly used in quality control to determine the maximum allowable number of defects in a product or batch, and SPC (Statistical Process Control) and Cpk (Process Capability Index) are tools used in statistical analysis and process control. While they are also important in maintaining quality, they are not directly associated with consumer's risk.

Question 20

In a double-sampling plan, a second sample may not be taken if the results of the first sample are conclusive.

Accepted Answer

In a double-sampling plan, the decision to take a second sample is based on the results of the first sample. If the results are inconclusive or borderline, a second sample may be taken to ensure a more accurate judgment. However, if the results of the first sample are conclusive, a second sample is unnecessary and not taken. Therefore, the statement is true.

Quiz 15: Acceptance Sampling– Static