Certified Quality Inspector & Reliability Engineer Flashcards

A quality inspector finds that 12 out of 200 sampled parts are nonconforming. What is the proportion nonconforming (p)?

Answer: 0.06

p = 12/200 = 0.06, representing the fraction of defective parts in the sample.

Which reliability measure describes the probability that a system performs its required function for a specified time under stated conditions?

Answer: Reliability

Reliability is formally defined as the probability of failure-free performance over a given time period under specified conditions.

On a control chart, which condition indicates a process is out of statistical control?

Answer: Seven consecutive points on one side of the centerline

Seven consecutive points on one side of the centerline is a Western Electric rule indicating a non-random shift in the process mean.

A bearing has a Mean Time Between Failures (MTBF) of 500 hours. What is its failure rate (λ)?

Answer: 0.002 failures/hour

Failure rate λ = 1/MTBF = 1/500 = 0.002 failures per hour for exponentially distributed failures.

Which sampling plan type is used when a decision must be made after inspecting only one sample?

Answer: Single sampling

Single sampling plans require one fixed sample to be drawn and inspected before making an accept/reject decision.

In a Failure Mode and Effects Analysis (FMEA), the Risk Priority Number (RPN) is calculated as:

Answer: Severity × Occurrence × Detection

RPN = Severity × Occurrence × Detection, and is used to prioritize failure modes for corrective action.

A micrometer reads 0.2510 inches on a nominal 0.250-inch gauge block. The measurement error is best described as:

Answer: 0.001 inch of bias

A consistent offset from the known true value is bias (systematic error), not random variation.