Quality Assurance & Process Control Flashcards

A control chart shows several consecutive points trending upward toward the upper control limit. This pattern is called a:

Answer: Run or trend

A series of consecutive points moving in the same direction is called a run or trend, indicating a non-random shift in the process.

Which sampling method involves dividing a population into groups and randomly selecting samples from each group?

Answer: Stratified sampling

Stratified sampling divides the population into subgroups (strata) and samples from each, ensuring representation across all groups.

The process capability ratio Cpk differs from Cp because Cpk accounts for:

Answer: Process centering relative to specification limits

Cpk measures capability while accounting for how well the process mean is centered between the specification limits, unlike Cp which only measures spread.

A fishbone diagram is primarily used to:

Answer: Identify root causes of a quality problem

A fishbone (Ishikawa) diagram organizes potential causes of a problem into categories to help identify root causes.

In acceptance sampling, the Acceptable Quality Level (AQL) represents:

Answer: The worst quality level still acceptable to the producer

AQL is the maximum percent defective that can be considered satisfactory as a process average for acceptance sampling purposes.

Which type of measurement error occurs when the same operator gets different results measuring the same part repeatedly?

Answer: Repeatability

Repeatability is the variation in measurements taken by the same operator using the same gauge on the same part under the same conditions.

A poka-yoke device is best described as:

Answer: An error-proofing mechanism that prevents or detects mistakes

Poka-yoke (mistake-proofing) devices are designed to prevent errors from occurring or to immediately detect them if they do occur.