CRE Risk Management & Maintenance 2 — Questions and Answers
Question 1: Which maintenance strategy is BEST suited for components where failure consequences are safety-critical and failure modes are detectable before function loss?
- Run-to-failure
- Condition-based maintenance (Correct answer)
- Scheduled replacement
- Design-out maintenance
Correct answer: Condition-based maintenance
Condition-based maintenance monitors detectable degradation signals to intervene before safety-critical failures occur.
Question 2: In a risk matrix, a hazard rated 'Catastrophic' severity with 'Improbable' likelihood is typically classified as:
- Acceptable risk
- Unacceptable risk
- ALARP region risk (Correct answer)
- Negligible risk
Correct answer: ALARP region risk
Catastrophic severity with low probability typically falls in the ALARP (As Low As Reasonably Practicable) region requiring justification to accept.
Question 3: The P-F interval in predictive maintenance refers to the time between:
- Planned maintenance and failure
- Potential failure detection and functional failure (Correct answer)
- Preventive action and fault correction
- Periodic inspection and forecast
Correct answer: Potential failure detection and functional failure
The P-F interval is the time from when a potential failure becomes detectable to when functional failure occurs.
Question 4: Which risk reduction technique involves adding redundant systems to reduce the probability of overall system failure?
- Consequence mitigation
- Fault tolerance (Correct answer)
- Hazard elimination
- Administrative controls
Correct answer: Fault tolerance
Fault tolerance uses redundancy so that individual component failures do not cause system-level failure.
Question 5: A Bow-Tie diagram in risk management combines which two analysis techniques?
- FMEA and RCA
- Fault Tree Analysis and Event Tree Analysis (Correct answer)
- HAZOP and FMECA
- RBD and Markov analysis
Correct answer: Fault Tree Analysis and Event Tree Analysis
A Bow-Tie diagram uses a Fault Tree on the left (causes leading to a hazard) and an Event Tree on the right (consequences).
Question 6: When applying RCM (Reliability-Centered Maintenance), the first question to ask about each function is:
- What are the failure modes?
- What is the item's function? (Correct answer)
- What are the consequences of failure?
- Is the failure hidden or evident?
Correct answer: What is the item's function?
RCM always begins by defining what functions the asset is required to perform in its operating context.
Question 7: Which maintenance tactic is most appropriate for a component with an Infant Mortality failure pattern (high early failure rate)?
- Time-directed replacement at fixed intervals
- Scheduled overhaul
- Burn-in testing before installation (Correct answer)
- Condition monitoring
Correct answer: Burn-in testing before installation
Burn-in or run-in testing screens out early failures before installation, reducing field failures from infant mortality.
CRE Risk Management & Maintenance 2
Which maintenance strategy is BEST suited for components where failure consequences are safety-critical and failure modes are detectable before function loss?