RAM Quality Assurance & Improvement 3 — Questions and Answers
Question 1: In reliability-centered maintenance (RCM), what is the primary criterion for selecting a maintenance task?
- Lowest cost of the task
- Task must be technically feasible and worth doing (Correct answer)
- Task must align with OEM recommendations only
- Task must eliminate all failure modes
Correct answer: Task must be technically feasible and worth doing
RCM requires that a maintenance task be both technically feasible (capable of detecting or preventing the failure) and worth doing (cost-effective relative to consequences).
Question 2: Which quality improvement tool maps the sequence of steps in a process to identify bottlenecks and non-value-added activities in a maintenance workflow?
- Histogram
- Value stream map (Correct answer)
- Control chart
- Affinity diagram
Correct answer: Value stream map
Value stream mapping visualizes the flow of materials and information through a process, revealing waste and improvement opportunities.
Question 3: A process capability index (Cp) of 1.33 indicates that the process:
- Is barely capable with no margin for shift
- Is capable with some room for variation (Correct answer)
- Is not capable and produces defects
- Equals the minimum acceptable Cpk
Correct answer: Is capable with some room for variation
A Cp of 1.33 means the process spread fits within the specification limits with a buffer, generally considered acceptable in many industries.
Question 4: In a RAM quality program, a 'preventive action' differs from a 'corrective action' in that it:
- Addresses a defect that has already occurred
- Addresses potential nonconformances before they occur (Correct answer)
- Is less formally documented
- Focuses only on equipment failure
Correct answer: Addresses potential nonconformances before they occur
Preventive action proactively eliminates the cause of a potential nonconformance, whereas corrective action reacts to an actual nonconformance.
Question 5: Which failure analysis method uses a logic diagram to systematically evaluate combinations of events that could lead to a specific top-level undesired event?
- Failure Mode and Effects Analysis (FMEA)
- Fault Tree Analysis (FTA) (Correct answer)
- Event Tree Analysis (ETA)
- Cause-and-Effect diagram
Correct answer: Fault Tree Analysis (FTA)
Fault Tree Analysis uses Boolean logic gates to model combinations of lower-level failures that result in a defined top-level failure event.
Question 6: A RAM quality engineer wants to monitor whether a process mean has shifted over time. The most appropriate control chart for individual measurements is:
- p-chart
- c-chart
- X-bar and R chart
- Individuals (I-MR) chart (Correct answer)
Correct answer: Individuals (I-MR) chart
The Individuals (I-MR) chart is used when data are collected as single measurements over time, monitoring both the process mean and variability.
Question 7: During a RAM quality review, Mean Active Maintenance Time (MAMT) is calculated. This metric primarily measures:
- Average time between system failures
- Average time required to perform all maintenance actions weighted by frequency (Correct answer)
- Time to restore a failed item to operating condition
- Total downtime divided by number of failures
Correct answer: Average time required to perform all maintenance actions weighted by frequency
MAMT is the weighted average of active corrective and preventive maintenance times, providing a composite maintainability performance indicator.
RAM Quality Assurance & Improvement 3
In reliability-centered maintenance (RCM), what is the primary criterion for selecting a maintenance task?