CRE Exam Questions

Which of the following BEST describes complete data?

What is the first step when conducting a maintainability study for a piece of existing equipment?

Which of the following techniques is MOST efficient when two nuisance variables are to be averaged out in an experimental design?

According to the definition of reliability, performance, over the expected or intended life, is one criterion. In order to obtain a measurement for reliability, the actual life (t)...

With respect to calculating a mission reliability, the time of the operating mission is:

If the mean time between failure has been determined to be a constant 13 hours for an experimental radar system, what is its reliability at t = 13.2 hours?

In a system with a constant failure rate, the relationship between the failure rate and MTBF is that the failure rate is

For the exponential model, the reliability at mean time to failure is about:

What is the reliability of the logic diagram to the below? (Assume statistical independence of all 3 components)

Which of the following statistical distributions can be used to compare sample means?

For human factors testing, the reliability engineer should understand and consider which of the following?

Detection of trends of product failure is MOST important when system failure are

Which mathematical model is characterized by linking exact relationships between variables?

A high incidence of failures has developed during aircraft acceptance testing. The identified failure is that an instrument panel light has malfunctioned on 6 of the last 10 aircra...

Which of the following is a discrete probability distribution?

The function below has a density distribution where X is a continuous random variable. What is the probability that X = 4.0?

Some keys to a successful reliability program include:

When designing experiments, which term describes the situation in which the effects of two factors are not separable?

The designer has certain tools for reliable design at his/her disposal. He/She can:

What is the expression for operation availability?

If the reliability goal for a 4 - hour mission is 0.9999 for a complex system, what system MTBF is required?

Which of the following is the BEST description of a process FMECA?

Time-to-market can be reduced MOST directly through the use of:

A software sneak circuit is BEST described as which of the following?

For continual improvement in product reliability which of the following tests is MOST desirable?

Which of the following is a continuous probability distribution?

In a life test of 4 batteries, failures were observed after 10, 30, and 40 hours. The 4th battery was tested 75 hours without failure, at which time the test was terminated. What a...

It is reliability's job to see that all the tasks outlined in the reliability program are:

A "fail-safe" requirement means:

A redundant system has 5 standby parallel components, with perfect switching. If each of the components have a reliability of 0.03 failures/hour, what is the system's reliability a...

A failure modes and effects analysis:

In standby parallel systems, imperfect switching means :

A prototype lot of a new design suspension spring underwent testing with these results: - Total hours accumulated: 12,000 - Number of Failures: 6 - Hours to failure: 202, 387, 461,...

Maintainability can be improved by:

If the average repair time for a system is 3 hours and the MTBMA is 122 hours, what is the operational availability?

The ratio of the variances of two independent samples from normal distributions with a common true variance has what type of distribution?

Reliability data is rarely complete. 50 units are placed on test for 50 hours. During the test several units fail. The remaining units are removed from testing at that point. Which...

Customer feedback and field data could NOT normally:

A failure which prevents the system from performing its mission would be classified as:

Basic sources of reliability data are:

A system made up of 5 series components has a design reliability of .96. Subsequently, 4 of the components have reliabilities apportioned to them of 0.992, 0.991, 0.994, and 0.992....

When performing trade-offs in evaluating parts for reliability, which of the following is LEAST important?

Which of the following statement is TRUE about maintainability?

Your company is investigating the use of Reliability Centered Maintenance. A RCM program would encompass which of the following features?

Which of the following is TRUE about an effective safety system?

In a production reliability acceptance test (PRAT) plan, the design/discrimination ratio is expressed as the ratio of

A reliability test was terminated after 171 hours based upon a pre-established plan. An estimate of mean-time-to-failure of 57 hours was obtained. The lower 95 percent confidence b...

If a company monitors field reliability using both 6 and 12 month MTBF moving average, a comparison of the average will generally show that the 12 month moving averages

Given a system requirement of maintainability (MTTR) of 4.7 hours. There are 5 devices in series with the following individual failure rates and MTTR. Determine the K factor.

Under a cost of reliability model, which of the following factors is used to determine warranty costs?