CRE Technical Standards and Specifications 2 — Questions and Answers
Question 1: Which MIL-STD standard governs reliability testing for electronic and electrical components used in military applications?
- MIL-STD-785
- MIL-STD-883 (Correct answer)
- MIL-STD-1629
- MIL-STD-217
Correct answer: MIL-STD-883
MIL-STD-883 establishes test methods and procedures for microelectronic devices used in military and aerospace applications.
Question 2: In IEC 61508, what is the term used to describe the probability that a safety function will be performed on demand?
- Probability of Failure on Demand (PFD) (Correct answer)
- Safety Integrity Level (SIL)
- Mean Time to Failure (MTTF)
- Diagnostic Coverage (DC)
Correct answer: Probability of Failure on Demand (PFD)
PFD (Probability of Failure on Demand) quantifies the likelihood that a safety function fails when a hazardous demand occurs, used for low-demand mode systems.
Question 3: What ASTM standard is most commonly referenced for tensile strength testing of metallic materials?
- ASTM E8/E8M (Correct answer)
- ASTM D638
- ASTM C39
- ASTM G31
Correct answer: ASTM E8/E8M
ASTM E8/E8M is the standard test method for tension testing of metallic materials, defining specimen geometry, testing procedures, and property calculations.
Question 4: Which SAE standard defines the reliability program requirements for development and production of aerospace and defense systems?
- SAE J1739
- SAE ARP4754 (Correct answer)
- SAE ARP4761
- SAE AS9100
Correct answer: SAE ARP4754
SAE ARP4754 provides guidelines for development of civil aircraft and systems, including reliability and safety processes during the design lifecycle.
Question 5: Under ISO 9001:2015, what is the primary purpose of a design validation activity?
- Confirm that design outputs meet design input requirements
- Ensure the product meets the needs of the intended use (Correct answer)
- Verify manufacturing processes are capable
- Review supplier qualification documentation
Correct answer: Ensure the product meets the needs of the intended use
Design validation under ISO 9001 confirms that the resulting product can fulfill the requirements for the specified application or intended use.
Question 6: The Bellcore/Telcordia SR-332 standard is primarily used to predict reliability of what type of equipment?
- Hydraulic systems
- Commercial electronic equipment and telecommunications hardware (Correct answer)
- Structural steel components
- Chemical processing vessels
Correct answer: Commercial electronic equipment and telecommunications hardware
Telcordia SR-332 (formerly Bellcore) provides a method for predicting the reliability of commercial electronic hardware using parts count and parts stress methods.
Question 7: In the context of ANSI/ASQ Z1.4, what does the term 'AQL' stand for and what does it define?
- Acceptable Quality Limit — the maximum defect rate considered acceptable for routine acceptance (Correct answer)
- Average Quality Level — the historical average defect rate of a process
- Assured Quality Lot — a lot that has passed all inspections
- Adjusted Quality Limit — a modified threshold based on process capability
Correct answer: Acceptable Quality Limit — the maximum defect rate considered acceptable for routine acceptance
AQL (Acceptable Quality Limit) in Z1.4 is the maximum defects-per-hundred units that can be considered satisfactory as a process average for acceptance sampling.
CRE Technical Standards and Specifications 2
Which MIL-STD standard governs reliability testing for electronic and electrical components used in military applications?