CRE Documentation and Reporting 3 — Questions and Answers
Question 1: In a Failure Reporting, Analysis, and Corrective Action System (FRACAS), which metric measures the average time from failure occurrence to the closure of a corrective action?
- Mean Time to Repair (MTTR)
- Corrective Action Cycle Time (Correct answer)
- Mean Logistics Delay Time (MLDT)
- Failure Report Closure Rate
Correct answer: Corrective Action Cycle Time
Corrective Action Cycle Time tracks the elapsed time between initial failure report and formal corrective action closure, indicating FRACAS process effectiveness.
Question 2: A Reliability Growth Management Plan (RGMP) document should include which of the following?
- Final acceptance test procedures only
- Planned growth curve, management strategy, and milestone gates (Correct answer)
- List of all subcontractor warranties
- Customer satisfaction survey results
Correct answer: Planned growth curve, management strategy, and milestone gates
An RGMP defines the reliability growth curve targets, the test-fix-test strategy, and decision gates at which growth progress is assessed.
Question 3: Which IEEE standard is most widely referenced for software reliability documentation and measurement?
- IEEE 1028 (Software Reviews and Audits)
- IEEE 1633 (Recommended Practice on Software Reliability) (Correct answer)
- IEEE 829 (Software Test Documentation)
- IEEE 730 (Software Quality Assurance Plans)
Correct answer: IEEE 1633 (Recommended Practice on Software Reliability)
IEEE 1633 provides recommended practice for software reliability measurement, modeling, and reporting throughout the software lifecycle.
Question 4: When a reliability engineer documents a Weibull analysis result with β < 1, what does this indicate about the failure population?
- Failures are occurring randomly with constant hazard rate
- Failures are increasing due to wear-out mechanisms
- Failures are decreasing over time, indicating infant mortality (Correct answer)
- The data set is too small to be valid
Correct answer: Failures are decreasing over time, indicating infant mortality
A Weibull shape parameter β < 1 corresponds to a decreasing hazard rate, characteristic of early-life (infant mortality) failures.
Question 5: A program's Reliability Qualification Test Report shows the demonstrated MTBF falls below the required MTBF. What is the correct next documented action?
- Immediately halt production and issue a stop-ship notice
- Document a waiver or deviation request and initiate a corrective action plan (Correct answer)
- Re-run the test with a larger sample to improve confidence
- Revise the requirement downward to match demonstrated performance
Correct answer: Document a waiver or deviation request and initiate a corrective action plan
When demonstrated reliability falls short, the engineering process requires a formal waiver/deviation document and a documented corrective action plan before proceeding.
Question 6: Which element of a Reliability Block Diagram (RBD) report is essential for auditors to verify that the model matches the actual system architecture?
- Software version used to draw the diagram
- Traceability matrix linking each block to its system component or assembly (Correct answer)
- Color coding scheme for active vs. standby blocks
- Analyst's professional certification number
Correct answer: Traceability matrix linking each block to its system component or assembly
A traceability matrix proves each RBD block corresponds to a real hardware or software element, ensuring the model accurately represents the system.
Question 7: In MIL-STD-2155-compliant failure analysis reports, the 'verification of fix' section documents what?
- Statistical proof that the corrective action eliminated the root cause (Correct answer)
- Customer satisfaction with the repair timeline
- The cost estimate for implementing the fix
- The technician's name who performed the repair
Correct answer: Statistical proof that the corrective action eliminated the root cause
Verification of fix requires documented evidence—test data or analysis—confirming that the implemented corrective action actually eliminated the identified root cause.
CRE Documentation and Reporting 3
In a Failure Reporting, Analysis, and Corrective Action System (FRACAS), which metric measures the average time from failure occurrence to the closure of a corrective action?