CMRP Reliability Data Analysis and Statistics

Question 1

What does MTBF stand for in reliability engineering?

Accepted Answer

Mean Time Between Failures

Answer

MTBF (Mean Time Between Failures) is the average time between successive failures of a repairable system and is a foundational reliability metric.

Question 2

Which formula correctly calculates failure rate (λ) from MTBF?

Accepted Answer

λ = 1 / MTBF

Answer

Failure rate (λ) equals 1/MTBF, representing the frequency of failures per unit of operating time.

Question 3

What does the bathtub curve illustrate in reliability engineering?

Accepted Answer

The failure rate pattern showing infant mortality, constant rate, and wear-out phases

Answer

The bathtub curve describes the three phases of equipment life: infant mortality (decreasing failure rate), useful life (constant rate), and wear-out (increasing failure rate).

Question 4

What is 'censored data' in the context of reliability analysis?

Accepted Answer

Data from units that have not failed or were removed before failure

Answer

Censored (suspended) data represents units that have not yet failed or were removed from service before failure, requiring special statistical methods for inclusion in reliability calculations.

Question 5

If a pump has an MTBF of 2,000 hours and an MTTR of 8 hours, what is its inherent availability?

Accepted Answer

99.6%

Answer

Availability = MTBF / (MTBF + MTTR) = 2000 / (2000 + 8) = 2000 / 2008 ≈ 0.996 or 99.6%.

CMRP - Certified Maintenance and Reliability Professional Practice Test

CMRP - Certified Maintenance and Reliability Professional Practice Test

CMRP Reliability Data Analysis and Statistics