Quality Control Procedures Flashcards

Which type of control chart is most appropriate for monitoring the proportion of defective items in a variable-size sample?

Answer: p-chart

The p-chart monitors the proportion (fraction) defective and accommodates variable sample sizes.

In acceptance sampling, what does the Operating Characteristic (OC) curve depict?

Answer: The probability of acceptance versus the lot defect rate

The OC curve plots the probability of accepting a lot against its true defect rate, showing discrimination power.

A process has a Cpk of 0.85. What does this indicate?

Answer: The process is not centered and is producing defects beyond specification limits

Cpk below 1.0 indicates the process is not capable; it is producing output outside at least one specification limit.

Which quality tool is specifically designed to determine which input variables most significantly affect an output variable?

Answer: Design of Experiments (DOE)

DOE systematically varies input factors to quantify their individual and combined effects on process outputs.

What is the purpose of a gage R&R (Repeatability and Reproducibility) study?

Answer: To quantify measurement system variation relative to process variation

Gage R&R assesses how much of the observed variation is due to the measurement system itself versus the actual process.

Under MIL-STD-1916, what sampling philosophy replaced AQL-based sampling?

Answer: Zero Acceptance Number (c=0) sampling

MIL-STD-1916 promotes zero acceptance number plans, emphasizing defect prevention over detection.

When a control chart shows a run of 8 consecutive points on one side of the centerline, this indicates:

Answer: A non-random pattern suggesting a process shift

Eight consecutive points on one side of the centerline is a Western Electric rule violation signaling a process mean shift.