Prep 1 Flashcards
6 cards from real Lean Six Sigma Black Belt Certification practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Prep 1 flashcards as text
In Measurement System Analysis (MSA), a %GR&R value greater than 30% indicates what about the measurement system?
Answer: The system is unacceptable and must be improved before use
Per AIAG MSA guidelines, %GR&R below 10% is acceptable, 10–30% may be acceptable based on the application, and above 30% means the measurement system is unacceptable — gauge variation is too large relative to total variation, making it unreliable for distinguishing good parts from bad.
Which control chart should be used to monitor the number of defects per unit when subgroup sizes vary from sample to sample?
Answer: u-chart
The u-chart tracks defects per unit and accommodates variable subgroup sizes, making it the correct choice when sample sizes change. The c-chart also counts defects but requires constant subgroup size. The p-chart and np-chart track the proportion or count of defective units, not defects.
A full factorial Design of Experiment (DOE) with 4 factors each set at 2 levels requires how many experimental runs without replication?
Answer: 16
A 2^k full factorial design requires 2^k runs. With k = 4 factors, that is 2^4 = 16 runs. This design allows estimation of all main effects and all two-, three-, and four-way interaction effects without any confounding.
A process yields Cp = 1.60 and Cpk = 0.75. What is the most accurate interpretation?
Answer: The process spread is sufficient but the mean is significantly shifted off-center
Cp measures potential capability based on spread alone without regard to centering. Cpk adjusts for how far the mean has drifted from the target. A high Cp with a low Cpk means the process distribution is narrow enough to fit within spec limits, but it is off-center, producing defects on one tail.
On a Value Stream Map (VSM), what does a kaizen burst symbol represent?
Answer: A location targeted for focused rapid improvement activity
The kaizen burst (starburst or lightning-bolt shape) is placed on a VSM to highlight areas where waste or problems have been identified and where a rapid improvement event — a kaizen workshop — should be conducted. It is an action flag, not a data symbol.
A hypothesis test produces a p-value of 0.03 against a pre-set significance level (α) of 0.05. What is the correct conclusion?
Answer: Reject H₀; sufficient evidence exists to support the alternative hypothesis
When the p-value (0.03) is less than the chosen significance level α (0.05), the decision rule is to reject the null hypothesis. This indicates the observed data is unlikely under H₀, providing statistical support for the alternative. The p-value is not the probability that H₀ is true — that is a common misinterpretation.