Question 1

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

Accepted Answer

Preventive maintenance involves regular maintenance and inspection of a system to identify potential issues and prevent breakdowns or failures. By conducting these inspections and maintenance tasks on a regular basis, we can determine when a system needs service or repair before it breaks down completely.

Question 2

Failures are tolerable as long as their results are not catastrophic.

Accepted Answer

False

Question 3

Small standard deviations in the MTBF distribution of a machine tend to support a policy of breakdown maintenance for that machine.

Accepted Answer

Small standard deviations in the MTBF (mean time between failures) distribution of a machine actually support a policy of preventive maintenance, as it indicates that the machine is consistently reliable and less likely to experience unexpected breakdowns.

Question 4

The reliability of a system in which each individual component must function in order for the entire system to function,and in which each component has its own unique reliability,independent of other components,is the product of the probabilities of each of those components.

Accepted Answer

This statement describes the product rule of independent probabilities, which applies to systems with independent components. The overall reliability of the system is the product of the individual component reliabilities.

Question 5

Preventive maintenance is reactive.

Accepted Answer

Preventive maintenance is actually proactive, as it involves regularly scheduled maintenance tasks in order to prevent potential issues before they occur.

Question 6

Maintenance includes all activities involved in keeping a system's equipment in working order.

Accepted Answer

Maintenance refers to the various activities involved in ensuring that a system's equipment is kept in good working order. This can include cleaning, inspection, repair, replacement, and other activities necessary to keep the system running smoothly. Without proper maintenance, equipment can become worn, damaged, or even dangerous, which can lead to costly repairs or even accidents.

Question 7

The product failure rate is the percentage of failures among the total number of products tested.

Accepted Answer

The product failure rate is calculated by dividing the number of failed products by the total number of products tested and expressing the result as a percentage. So, the statement is true.

Question 8

If the mean time between failures has been calculated to be 2,000 hours,then FR(N)= 0.0005 failures/unit-hour.

Accepted Answer

The calculation for FR(N) is (1/MTBF) = (1/2000) = 0.0005 failures/unit-hour. Therefore, the statement is true.

Question 9

A redundant part decreases reliability if the reliability of the redundant part is lower than that of the part it is backing up.

Accepted Answer

The answer of A redundant part decreases reliability if the...

Question 10

The Pickering Nuclear Power Station in Ontario uses a proper maintenance management program,and devotes significant dollar and labour resources to power plant maintenance,because the costs of unexpected failure are incredibly high.

Accepted Answer

The statement mentions that the Pickering Nuclear Power Station uses a proper maintenance management program and devotes significant resources to maintenance to avoid unexpected failure, which indicates that the statement is true.

Question 11

Infant mortality refers to the high failure rate often encountered in the very early stages of the lifetime of a product.

Accepted Answer

The answer of Infant mortality refers to the high failure...

Question 12

The MTBF distributions of products,machines,or processes that have "settled in," or gone beyond the infant mortality phase,often follow the normal distribution.

Accepted Answer

This is generally true, as the normal distribution is often used to model reliability data of products, machines, and processes in the steady-state phase. However, other distributions like Weibull or lognormal may also be used depending on the specifics of the data.

Question 13

A redundant part or component increases reliability because it is connected in parallel,not in series.

Accepted Answer

When a redundant component is connected in parallel, it provides an alternate path for the current to flow even if the primary component fails. This improves reliability compared to connecting components in series, where failure of one component results in failure of the entire system.

Question 14

Reliability is the probability that a machine part or product will function properly for a specified time regardless of conditions.

Accepted Answer

Reliability is the probability that a machine part or product will function properly for a specified time under stated conditions, not regardless of conditions. Conditions such as operating environment, maintenance, and usage intensity significantly affect reliability.

Question 15

Preventive maintenance is nothing more than keeping the equipment and machinery running.

Accepted Answer

Preventive maintenance involves regularly scheduled inspections, repairs, and replacements of parts to prevent breakdowns and extend the life of equipment and machinery. It is not just about keeping them running, but rather about proactively identifying and addressing potential issues before they turn into major problems.

Question 16

Recording the maintenance history of processes,machines,or equipment is important for preventive maintenance,but largely irrelevant for breakdown maintenance.

Accepted Answer

The answer of Recording the maintenance history of processes,machines,or equipment...

Question 17

The MTBF (mean time between failures)is calculated as the reciprocal of the number of failures during a period of time.

Accepted Answer

The answer of The MTBF (mean time between failures)is calculated...

Question 18

When identifying the optimal maintenance policy,the cost of inventory maintained to compensate for the downtime is a cost often ignored.

Accepted Answer

The cost of inventory maintained to compensate for downtime is often overlooked, but it should be considered when determining the optimal maintenance policy.

Question 19

Adding an additional part to a component or product ordinarily reduces reliability by introducing an additional source of failure.

Accepted Answer

This statement is generally true. Introducing an additional part or component can increase the likelihood of failure due to factors such as increased complexity, potential for misalignment or poor fitting, and increased wear and tear. However, there may be cases where the additional part improves reliability through redundancy or other design features.

Question 20

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

Accepted Answer

According to the full cost view of maintenance, a policy of preventive maintenance is more cost-effective in the long run. Therefore, more firms would choose a policy of preventive maintenance instead of breakdown maintenance.

Quiz 17: Maintenance and Reliability