Certified Quality Inspector & Reliability Engineer Flashcards

System availability (A) is correctly expressed as:

Answer: MTBF / (MTBF + MTTR)

Availability A = MTBF / (MTBF + MTTR), representing the proportion of time a system is operational.

A quality engineer wants to determine whether there is a linear relationship between oven temperature and tensile strength. Which tool is most appropriate?

Answer: Scatter diagram with regression analysis

Scatter diagrams visually show correlation, and regression analysis quantifies the linear relationship between two continuous variables.

According to MIL-HDBK-217, what is the primary method for predicting electronic component reliability?

Answer: Parts count and parts stress reliability prediction

MIL-HDBK-217 provides parts count and parts stress methods to predict failure rates of electronic components based on part type and operating conditions.

During a first article inspection (FAI), the inspector is verifying that:

Answer: The first unit from a new production process meets all design requirements

FAI confirms that the production process, tooling, and materials produce a product that fully conforms to design requirements before full production begins.

A reliability test places 20 units on test; 4 fail during 1000 hours of testing. Using the time-terminated test, what is the estimated MTBF?

Answer: 5,000 hours

MTBF = Total unit-hours / Number of failures = (20 × 1000) / 4 = 20,000 / 4 = 5,000 hours.

Which sampling standard is most commonly referenced in the US for attribute inspection sampling plans based on AQL?

Answer: ANSI/ASQ Z1.4

ANSI/ASQ Z1.4 is the current US standard for attribute sampling inspection plans indexed by AQL (formerly MIL-STD-105E).

In a Design of Experiments (DOE), a full factorial design with 3 factors each at 2 levels requires how many experimental runs (excluding replication)?

Answer: 8

A 2³ full factorial design requires 2³ = 8 experimental runs to test all combinations of 3 factors at 2 levels.