Quality Control & Assurance Flashcards

Which statistical tool is used to separate the vital few causes of defects from the trivial many?

Answer: Pareto chart

A Pareto chart applies the 80/20 rule to rank defect causes so teams focus on the vital few that drive most problems.

A process capability index (Cpk) of 1.33 indicates that the process is:

Answer: Capable with a 4-sigma margin from the nearest specification limit

Cpk = 1.33 corresponds to a 4-sigma separation from the nearest spec limit, which is the traditional minimum acceptable capability.

What does a C-chart monitor in statistical process control?

Answer: The count of defects on a single unit of fixed size

A C-chart tracks the number of defects (nonconformities) per inspection unit when the sample size is constant.

During a measurement system analysis (MSA), 'reproducibility' refers to:

Answer: Variation when different operators measure the same part

Reproducibility is the variation in measurements taken by different appraisers using the same gauge on the same parts.

Which quality cost category includes scrap, rework, and warranty repairs?

Answer: Internal and external failure costs

Scrap and rework are internal failure costs; warranty repairs are external failure costs — both fall under the failure cost category.

An OC (Operating Characteristic) curve for an acceptance sampling plan shows the relationship between:

Answer: Incoming lot quality and probability of acceptance

The OC curve plots lot percent defective (X-axis) against the probability that the sampling plan will accept that lot (Y-axis).

In FMEA, the Risk Priority Number (RPN) is calculated as:

Answer: Severity × Occurrence × Detection

RPN = Severity × Occurrence × Detection, and higher RPN values flag failure modes requiring priority corrective action.