Exam 20: Maintenance and Reliability

DuLarge Marine manufactures diesel engines for shrimp trawlers and other small commercial boats. One of their CNC machines has caused several problems. Over the past 30 weeks, the machine has broken down as indicated below. Each time the machine breaks down, the firm loses an average of $3,000 in time and repair expenses. Number of breakdowns per week 0 1 2 3 4 Frequency (Number of weeks that breakdowns occurred) 8 3 5 9 5 What is the expected breakdown cost per week?

Define reliability.

A manufacturing firm wants to apply 6-sigma standards to its automated tolerance-check process. Suppose that each scanner makes the correct decision only 50% of the time, however only 1 correct decision by any scanner makes the entire process a success. How many scanners are needed to ensure 6-sigma quality?

For a machine to be a good candidate for preventive maintenance

Preventive maintenance implies that we can determine when a system needs service or will need repair.

Which of the following best illustrates the importance of employee involvement in achieving successful maintenance and reliability?

Autonomous maintenance occurs when

Ten high-intensity bulbs are tested for 100 hours each. One failed at 10 hours; all others completed the test. Calculate FR(%), FR(N) and MTBF.

DuLarge Marine manufactures diesel engines for shrimp trawlers and other small commercial boats. One of their CNC machines has caused several problems. Over the past 30 weeks, the machine has broken down as indicated below. Number of breakdowns per week 0 1 2 3 4 Frequency (Number of weeks that breakdowns occurred) 8 3 5 9 5 What is the expected number of breakdowns per week?

Ten high-intensity bulbs are tested for 100 hours each. One failed at 40 hours; another failed at 70 hours; all others completed the test. Calculate FR(%), FR(N), and MTBF.

__________ is the use of a component in parallel to raise reliabilities.

Orlando Utilities Commission uses a computerized maintenance management program, and devotes significant dollar and labor resources to power plant maintenance, because the costs of unexpected failure are incredibly high.

Suppose that a three stage process had reliability ratings of .7, .8, and .9 at each station and that a failure at any station represented a failure for the entire process. If each station is given a redundant check with .9 reliability, what is the increase in system reliability?

The "full cost view of maintenance" results in more firms choosing a policy of breakdown maintenance, when compared to the "traditional view of maintenance."

"High reliability can be achieved in a product without having high reliability in the component parts. In fact, any reliability target, no matter how high, can be achieved with only mediocre parts, so long as enough of them are present." Discuss; an example may help.

An optimal maintenance policy strikes a balance between the costs of breakdown and preventive maintenance so that the total cost of maintenance is at a minimum.

Which of the following costs tend to be ignored in determining the optimal maintenance policy?

Which one of the following statements about maintenance is true?

As a firm's maintenance commitment increases,

What is the impact on system reliability of adding parts or components in parallel?