CLS Risk Assessment & Mitigation 2 — Questions and Answers
Question 1: Which failure mode analysis technique maps out all possible failure modes and their effects on system performance?
- Root Cause Analysis (RCA)
- Failure Mode and Effects Analysis (FMEA) (Correct answer)
- Fault Tree Analysis (FTA)
- Hazard and Operability Study (HAZOP)
Correct answer: Failure Mode and Effects Analysis (FMEA)
FMEA systematically identifies potential failure modes and evaluates their effects on system performance to prioritize risk mitigation.
Question 2: A lubrication technician notices that a gearbox oil temperature has increased by 15°C above its normal operating range. What is the PRIMARY risk this indicates?
- Increased oil viscosity leading to poor flow
- Accelerated lubricant oxidation and degradation (Correct answer)
- Decreased wear particle generation
- Improved additive activation
Correct answer: Accelerated lubricant oxidation and degradation
Elevated temperature accelerates lubricant oxidation, which degrades the base oil and additives, reducing service life and increasing wear risk.
Question 3: When assessing contamination risk in a hydraulic system, which particle size range is considered most damaging to hydraulic components?
- Particles smaller than 1 micron
- Particles in the 5–15 micron range (Correct answer)
- Particles larger than 100 microns
- Particles between 50–75 microns
Correct answer: Particles in the 5–15 micron range
Particles in the 5–15 micron range are most damaging because they are large enough to cause wear but small enough to pass through clearances repeatedly.
Question 4: What does a Risk Priority Number (RPN) in FMEA represent?
- The cost of a failure event
- The product of severity, occurrence, and detection ratings (Correct answer)
- The probability of catastrophic failure only
- The sum of all identified failure modes
Correct answer: The product of severity, occurrence, and detection ratings
RPN = Severity × Occurrence × Detection, and is used to prioritize which failure modes require the most urgent corrective action.
Question 5: Which lubrication-related risk is most directly mitigated by implementing a scheduled oil sampling program?
- Incorrect lubricant selection
- Undetected lubricant degradation leading to equipment failure (Correct answer)
- Lubricant cross-contamination during delivery
- Improper relubrication interval scheduling
Correct answer: Undetected lubricant degradation leading to equipment failure
Regular oil sampling detects early signs of lubricant degradation, contamination, and wear before they progress to equipment failure.
Question 6: A plant switches from mineral oil to a synthetic lubricant in a compressor. What compatibility risk must be evaluated FIRST?
- Change in oil pressure requirements
- Seal and gasket material compatibility with the synthetic base fluid (Correct answer)
- Increased lubricant cost impact on budget
- Synthetic oil's effect on bearing load capacity
Correct answer: Seal and gasket material compatibility with the synthetic base fluid
Synthetic lubricants, especially PAO or ester-based types, can swell or shrink elastomeric seals differently than mineral oils, potentially causing leaks.
Question 7: What risk management strategy involves accepting a known risk because the cost of mitigation exceeds the potential loss?
- Risk avoidance
- Risk transfer
- Risk retention (acceptance) (Correct answer)
- Risk reduction
Correct answer: Risk retention (acceptance)
Risk retention means knowingly accepting a risk when mitigation costs outweigh potential losses, often documented in a formal risk register.
CLS Risk Assessment & Mitigation 2
Which failure mode analysis technique maps out all possible failure modes and their effects on system performance?