CRE Risk Management & Maintenance 3

Question 1

Which quantitative risk metric represents the probability of an individual being harmed per year due to a specific hazard?

Accepted Answer

Individual risk

Answer

Individual risk is expressed as the annual probability that a specific person will be harmed by the hazard.

Question 2

In FMECA, the Criticality Number (Cm) is calculated by multiplying failure mode ratio, failure rate, and:

Accepted Answer

Mission time

Answer

Cm = failure mode ratio × item failure rate × mission time, giving the expected number of critical failures per mission.

Question 3

The concept of 'safe-life' in maintenance refers to a component that:

Accepted Answer

Is replaced at a fixed interval before expected failure

Answer

Safe-life components are retired at a predetermined usage limit to prevent in-service failure regardless of apparent condition.

Question 4

An FTA uses which logic gate to represent a condition where ALL inputs must occur for the output event to occur?

Accepted Answer

AND gate

Answer

An AND gate in a Fault Tree requires all input events to be TRUE simultaneously for the output event to occur.

Question 5

Which maintenance performance metric measures the proportion of total time that a system is available for use?

Accepted Answer

Availability

Answer

Availability = Uptime / (Uptime + Downtime), representing the fraction of time the system is in a functioning state.

(CRE) Certified Reliability Engineer Practice Test