MMC Asset Management & Reliability 3 — Questions and Answers
Question 1: In an FMEA, the Risk Priority Number (RPN) is calculated as:
- Severity × Occurrence
- Severity × Occurrence × Detection (Correct answer)
- Occurrence × Detection
- Severity + Occurrence + Detection
Correct answer: Severity × Occurrence × Detection
RPN = Severity × Occurrence × Detection, providing a single numeric score to prioritize failure modes for corrective action.
Question 2: Which spare parts classification strategy designates parts that, if unavailable, would cause a production shutdown lasting more than 24 hours as the highest priority?
- ABC analysis
- Critical, Essential, Desirable (CED) classification (Correct answer)
- EOQ model
- VMI classification
Correct answer: Critical, Essential, Desirable (CED) classification
CED (Critical, Essential, Desirable) classification ranks spare parts by the operational impact of their unavailability, placing production-stopping items in the Critical category.
Question 3: A facility uses oil analysis on a gearbox and finds a sudden increase in iron and silicon particles. What is the most likely conclusion?
- Normal wear — no action needed
- Gear tooth wear accelerated by contamination ingress (Correct answer)
- Bearing outer race failure
- Oil oxidation without mechanical damage
Correct answer: Gear tooth wear accelerated by contamination ingress
High iron particles indicate gear or bearing wear, and elevated silicon typically signals dirt ingress through a compromised seal, together pointing to accelerated wear from contamination.
Question 4: The concept of 'hidden failure' in RCM refers to a failure that:
- Occurs without any warning symptoms
- Is not evident to the operating crew under normal circumstances (Correct answer)
- Happens below the detection threshold of condition monitoring
- Only occurs during plant shutdowns
Correct answer: Is not evident to the operating crew under normal circumstances
A hidden failure is one that cannot be detected by the operating crew during normal operation, typically associated with protective devices like alarms or safety valves.
Question 5: Under ISO 14224, what is the primary purpose of collecting failure data in a standardized format?
- Meet regulatory reporting requirements
- Enable benchmarking and reliability analysis across industries (Correct answer)
- Automate maintenance scheduling
- Reduce spare parts inventory
Correct answer: Enable benchmarking and reliability analysis across industries
ISO 14224 standardizes failure data collection to allow meaningful benchmarking, reliability modeling, and analysis across different organizations and industries.
Question 6: Which maintenance strategy is MOST appropriate for a non-critical component with a random failure pattern and cheap replacement cost?
- Predictive maintenance using vibration analysis
- Reliability-centered maintenance analysis
- Run-to-failure (corrective maintenance) (Correct answer)
- Time-based preventive replacement
Correct answer: Run-to-failure (corrective maintenance)
When a failure has no safety consequences, is random in nature, and replacement is inexpensive, run-to-failure is often the most cost-effective strategy.
Question 7: What is 'inherent reliability' of an asset?
- Reliability achieved after extensive modification
- The reliability built in through design and manufacturing before maintenance is applied (Correct answer)
- Reliability measured during the first year of operation
- Reliability calculated using field failure data
Correct answer: The reliability built in through design and manufacturing before maintenance is applied
Inherent reliability is the level of reliability built into an asset through its design and manufacturing quality, representing the best performance achievable without design changes.
MMC Asset Management & Reliability 3
In an FMEA, the Risk Priority Number (RPN) is calculated as: