Exam 12: Statistically Based Quality Improvement for Attributes

Use the following table to answer the question(s) below. -A producer of contact lenses regularly takes samples of 100 lenses and inspects them for scratches. If a lens has a single scratch, it cannot be sold. The results of 10 samples are shown. What is the average proportion defective?

A system is composed of three components. Two of the items are in parallel and have reliabilities of 0.95 and 0.90. The third item has a reliability of 0.98 and this item is in series with the first combination. What is the overall system reliability?

What is the reliability of a product with a failure rate of 0.002 per operating hour and a useful life of 1000 hours?

What is the system availability for something that has a mean time between failures of 50 hours and needs an average of 1 hour to repair when it does fail?

Two components of reliability 0.95 are in parallel and this subsystem is connected in series to a component with a reliability of 0.90. The overall system reliability is ________.

Use the following table to answer the question(s) below. -The producers of the Yugo automobile periodically inspect samples of 80 hoods for dents and scratches. A single flaw in a hood renders it unsuitable for installation in one of their fine automobiles. The results of the last 10 samples are shown.. What is the center line for the np chart?

Which of the following is an example of a statistic based on an attribute?

What is a np chart and how is it similar to or different than a p chart?

Describe the development and interpretation of the bathtub curve.

The producers of the Yugo automobile periodically inspect samples of 80 hoods for dents and scratches. A single flaw in a hood renders it unsuitable for installation in one of their fine automobiles. The results of the last 10 samples are shown.. What are the lower and upper control limits for the np chart?

Fifty defibrillators are tested for 48 hours per machine. Of all the machines tested, 2 experience malfunctions during the test. What is the failure rate for the machines?

A system is to be composed of 10 identical components in series. What is the lowest reliability component that can be used in order to have an overall system reliability of 0.90?

A system is to be composed of 5 identical components in series. What is the lowest reliability component that can be used in order to have an overall system reliability of 0.90?

A manufacturer of FAX machines checks samples of 50 units for functionality at the conclusion of the assembly process. The results of 10 samples are shown below: What sample is out of control?

State the five types of attributes.

Reliability models assume independence between failure events.

Use the following table to answer the question(s) below. -A producer of contact lenses regularly takes samples of 100 lenses and inspects them for scratches. If a lens has a single scratch, it cannot be sold. The results of 10 samples are shown. What are the lower and upper 3-sigma control limits?

Which of the following is not used for monitoring defects or defectives?

The horizontal axis on the bathtub curve is reliability.

The shape of the process line in a p chart and an np chart plot is always identical if the same data are used.