Online Access Free CRE Exam Questions

A system is made up to several identical parts of varying age. The reliability of each of these parts is given by R( t) = e - λt where λ is the failure rate in failures per hour and t is the operating time in hours.
Which of the following is TRUE about the reliability of these parts?
Response:

• A.The failure rate of the system is given by the product of the individual part reliabilities.
• B.The failure rate of the system is given by the product of the individual part failure rates.
• C.Each of the parts has the same probability of failing during a given period of time.
• D.The oldest part is expected to fail first.

A company has produced a new module. The failure data on 40 returns are shown below.

If the time to failure follows a normal distribution, what is the probability that time to failure exceeds 20 hours ?
Response:

• A.0.972
• B.0.028
• C.0.950
• D.0.050

In which of the following distribution is the standard deviation equal to the mean?
Response:

• A.Exponential.
• B.Negative binomial.
• C.Poisson.
• D.Binomial.

For human factors testing, the reliability engineer should understand and consider which of the following?
I. Sight capabilities.
II. Touch capabilities.
III. Audio capabilities.
IV. Thermal capabilities.
V. Vibration capabilities.
Response:

• A.I, II, III, IV
• B.II, III IV, V
• C.I, II, III
• D.I, II, III, IV, V

In a design team environment, the reliability function can influence product reliability principally by:
Response:

• A.Conducting internal and external failure analyses.
• B.Providing repair and maintenance service information.
• C.Integrating the reliability requirements into product design.
• D.Developing reliability tests and procedures.