Question 1

A system is composed of three components A, B, and C. All three must function for the system to function. There are currently no backups in place. The system has a reliability of 0.966. If a backup is installed for component A, the new system reliability will be
A) unchanged
B) less than 0.966
C) greater than it would be if a backup were also installed for component B
D) greater than 0.966
E) none of the above

Accepted Answer

Installing a backup for component A would increase the system reliability, meaning the probability of all three components functioning together would be higher than 0.966. Therefore, the new system reliability would be greater than 0.966 if a backup is installed for component A.

Question 2

Which of the following is a reliability tactic?
A) improving individual components
B) increasing repair speed
C) providing redundancy
D) A and C
E) A, B, and C

Accepted Answer

Improving individual components and providing redundancy are both reliability tactics. Increasing repair speed is a maintenance tactic rather than a reliability tactic. Therefore, the best choice is D, which includes the two reliability tactics.

Question 3

Simulation models and expert systems are useful tools for enhancing maintenance.

Accepted Answer

Simulation models and expert systems can help increase efficiency and accuracy in maintenance activities by predicting potential issues, providing diagnostic guidance, and offering recommended solutions.

Question 4

Which of the following statements about maintenance at Orlando Utilities Commission is false?
A) There are at least two types of preventive maintenance, including an annual maintenance and a less frequent overhaul schedule.
B) Its preventive maintenance program has earned the company top rankings and its competitive advantage.
C) Each power-generating unit is taken off-line every three years for a complete overhaul.
D) Each of its power-generating units is taken off-line for maintenance every one to three weeks.
E) Costs associated with breakdowns are several times higher than costs arising from preventive maintenance.

Accepted Answer

The statement that each power-generating unit is taken off-line for maintenance every one to three weeks is false. The article states that maintenance is done on a schedule, including an annual maintenance and less frequent overhaul schedule, but does not mention weekly maintenance.

Question 5

A system has three components in series with reliabilities 0.9, 0.7, and 0.5. System reliability is
A) 0.315
B) 0.500
C) 0.700
D) 0.900
E) 2.100

Accepted Answer

The reliability of a series system is the product of the reliabilities of its components. Thus, the system reliability is 0.9 * 0.7 * 0.5 = 0.315.

Question 6

A job consists of a series of three tasks. Task 1 is performed correctly 98% of the time, task 2 is performed correctly 99% of the time, and task 3 is performed correctly 97% of the time. The reliability of this job is
A) 91.27%
B) 94.11%
C) 97.00%
D) 98.00%
E) 99.00%

Accepted Answer

The formula for reliability of a series system is: R = (R1)(R2)(R3) where R1, R2, and R3 are the reliability of each task. 
Substitute the given values: R = (0.98)(0.99)(0.97) = 0.9411 or 94.11%. Therefore, the best choice is B.

Question 7

Components A, B, and C are connected in series. Component D is connected in parallel to component B. Which of the following statements is true?
A) The system works only if A works, B or C works, and D works.
B) Component B must work for the system to work.
C) The system works when A works, C, works, and either B or D works.
D) Components B and C are backups to A.
E) The system works if D works, and any of A, B, or C works.

Accepted Answer

In a series circuit, all components must work for the circuit to function. Therefore, component A, B, and C must work for the system to work.

Component D is connected in parallel to component B, which means that it provides an alternate path for current to flow. This means that either B or D can work for the system to function. Therefore, the system works when A works, C works, and either B or D works. Choice C is the only answer that describes this correctly.

Question 8

What is the reliability of a four-component product, with components in series, and component reliabilities of .90, .95, .98, and .99?
A) under 0.83
B) 0.90
C) 0.955
D) no less than .99
E) none of the above

Accepted Answer

The answer of What is the reliability of a four-component...

Question 9

The objective of maintenance and reliability is to maintain the capability of the system.

Accepted Answer

The objective of maintenance and reliability is to ensure that the system can continue to fulfill its intended function in its operating environment. This includes maintaining the capability of the system, as well as its efficiency, safety, and availability.

Question 10

The objective of maintenance and reliability is to
A) ensure that breakdowns do not affect the quality of the products
B) ensure that no breakdowns will ever occur
C) ensure that preventive maintenance costs are kept as low as possible
D) maintain the capability of the system
E) ensure that maintenance employees are fully utilized

Accepted Answer

The objective of maintenance and reliability is to maintain the capability of the system, which means ensuring that it can continue to function as intended and meet performance requirements. This includes preventing breakdowns and addressing equipment issues in a timely and efficient manner, but also involves broader efforts such as optimizing maintenance strategies and improving the overall reliability of the system. The other options are either impractical (B), too narrow in scope (A and C), or potentially counterproductive (E).

Question 11

What is the reliability of the three components connected in series shown below? 
A) 0.799425
B) 0.85000
C) 0.91333
D) 0.95000
E) 2.79

Accepted Answer

The answer of What is the reliability of the three...

Question 12

While breakdowns occur randomly, their frequency is somewhat predictable through such tools as the product failure rate, MTBF, and the breakdown costs model.

Accepted Answer

The statement is true. Predictive tools such as the product failure rate, mean time between failures (MTBF), and breakdown costs model can provide insights into the frequency and potential cost of breakdowns.

Question 13

A system has three components in parallel with reliabilities 0.9, 0.7, and 0.5. System reliability is
A) 0.315
B) 0.700
C) 0.900
D) 0.985
E) 2.100

Accepted Answer

The system reliability in parallel connection is given by the formula:  R = 1 - (1-R1)(1-R2)(1-R3), where R1, R2, and R3 are the reliabilities of the three components. By substituting the given values, we get: R = 1 - (1-0.9)(1-0.7)(1-0.5) = 0.985. Therefore, the best choice is D.

Question 14

TPM (total productive maintenance) is an application of TQM (total quality management) principles to the area of maintenance.

Accepted Answer

TPM focuses on maximizing equipment effectiveness, quality, and reliability through proactive maintenance practices and employee involvement, while TQM is a management approach that aims to improve quality and customer satisfaction by involving all employees in continual improvement efforts. TPM is a specific application of TQM principles to maintenance.

Question 15

The probability that a product will function properly for a specified time under stated conditions is
A) functionality
B) maintenance
C) durability
D) reliability
E) fitness for use

Accepted Answer

The probability that a product will function properly for a specified time under stated conditions is referred to as its reliability. Therefore, option D is the best choice. The other options are related to the concept of the product's performance but do not specifically refer to its reliability.

Question 16

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.

Accepted Answer

This statement is true. An optimal maintenance policy aims to minimize the total cost of maintenance by balancing the costs of breakdown maintenance and preventive maintenance. Too much preventive maintenance can lead to excessive costs, while too little can increase the risk of breakdowns and also incur costs. Therefore, a balance is necessary to minimize overall maintenance costs.

Question 17

Consider a product with three components in series, with reliabilities of 0.90, 0.80, and 0.99 for components A, B, and C, respectively. Furthermore, component B uses a backup that also has a reliability of 0.80. What is the reliability of the system?
A) 0.50000
B) 0.71280
C) 0.80000
D) 0.85536
E) 3.49000

Accepted Answer

The reliability of the system can be found using the formula:

Rsystem = R1 * R2 * R3

where R1, R2, and R3 are the reliabilities of components A, B, and C, respectively.

However, component B uses a backup, so we need to use the parallel formula for R2 and Rbackup:

R2+backup = R2 + (1 - R2) * Rbackup

where R2 is the reliability of component B and Rbackup is the reliability of the backup.

Substituting the given values, we get:

R2+backup = 0.8 + (1 - 0.8) * 0.8 = 0.96

Now we can calculate the reliability of the system:

Rsystem = R1 * R2+backup * R3
Rsystem = 0.9 * 0.96 * 0.99
Rsystem = 0.85536

Therefore, the reliability of the system is 0.85536, which corresponds to answer choice D.

Question 18

As the number of components in a system connected in a series decreases, all other things being equal, the reliability of the system usually
A) increases
B) stays the same
C) decreases
D) increases, then decreases
E) decreases, then increases

Accepted Answer

When components are connected in a series, the failure of any single component can cause the entire system to fail. Therefore, as the number of components in a series decreases, the likelihood of a failure occurring also decreases, which increases the reliability of the system.

Question 19

A product has three components, A, B, and C, with reliabilities of 0.95, 0.98, and 0.995. Engineers intend to put a redundant component A that has reliability 0.70. With this change, system reliability will
A) fall by 20%
B) fall by 10% or less
C) rise
D) cannot determine from the information provided
E) none of the above

Accepted Answer

To find the new reliability, we need to use the formula for parallel components:
R_total = 1 - (1 - R_A)(1 - R_B)(1 - R_C)
where R_total is the reliability of the system with the redundant component A and R_A, R_B, and R_C are the reliabilities of components A (redundant), B, and C, respectively.

Substituting the given values, we get:
R_total = 1 - (1 - 0.70)(1 - 0.98)(1 - 0.995)
R_total = 0.99916

Therefore, the system reliability will rise to 0.99916, which is higher than the original reliability of 0.95. Therefore, the answer is C) rise.

Question 20

Which of the following best illustrates the importance of employee involvement in achieving successful maintenance and reliability?
A) Operator, machine, and mechanic are independent of one another.
B) Small standard deviations tend to favor preventive maintenance over breakdown maintenance.
C) Infant mortality in products can be decreased through improved owner's manuals and after-sales service and customer training.
D) Employee involvement through such elements as reward systems and power sharing combine with good maintenance and reliability procedures to improve capacity and reduce variability.
E) Empowered operators have higher competence at repairs than field service or depot service.

Accepted Answer

This choice emphasizes the importance of employee involvement in achieving successful maintenance and reliability through reward systems and power sharing. It highlights that effective maintenance and reliability are not just dependent on good procedures but also on involving and empowering employees to take ownership and responsibility for maintaining equipment, resulting in improved capacity and reduced variability. The other choices mention factors such as independent roles of employees, the importance of preventive maintenance, improving owner's manuals, customer training, and repair competence, but they do not emphasize the importance of employee involvement in achieving successful maintenance and reliability.

Quiz 17: Maintenance and Reliability

A system is composed of three components A, B, and C. All three must function for the system to function. There are currently no backups in place. The system has a reliability of 0.966. If a backup is installed for component A, the new system reliability will be

Which of the following is a reliability tactic?

Simulation models and expert systems are useful tools for enhancing maintenance.

Which of the following statements about maintenance at Orlando Utilities Commission is false?

A system has three components in series with reliabilities 0.9, 0.7, and 0.5. System reliability is

A job consists of a series of three tasks. Task 1 is performed correctly 98% of the time, task 2 is performed correctly 99% of the time, and task 3 is performed correctly 97% of the time. The reliability of this job is

Components A, B, and C are connected in series. Component D is connected in parallel to component B. Which of the following statements is true?

What is the reliability of a four-component product, with components in series, and component reliabilities of .90, .95, .98, and .99?

The objective of maintenance and reliability is to maintain the capability of the system.

The objective of maintenance and reliability is to

What is the reliability of the three components connected in series shown below?

While breakdowns occur randomly, their frequency is somewhat predictable through such tools as the product failure rate, MTBF, and the breakdown costs model.

A system has three components in parallel with reliabilities 0.9, 0.7, and 0.5. System reliability is

TPM (total productive maintenance) is an application of TQM (total quality management) principles to the area of maintenance.

The probability that a product will function properly for a specified time under stated conditions is

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.

Consider a product with three components in series, with reliabilities of 0.90, 0.80, and 0.99 for components A, B, and C, respectively. Furthermore, component B uses a backup that also has a reliability of 0.80. What is the reliability of the system?

As the number of components in a system connected in a series decreases, all other things being equal, the reliability of the system usually

A product has three components, A, B, and C, with reliabilities of 0.95, 0.98, and 0.995. Engineers intend to put a redundant component A that has reliability 0.70. With this change, system reliability will

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