CPS Advanced Techniques & Methods 2 — Questions and Answers
Question 1: Which statistical tool is used to determine the minimum number of samples needed to detect a process shift of a specified magnitude?
- Control chart
- Power analysis (Correct answer)
- Pareto analysis
- Fishbone diagram
Correct answer: Power analysis
Power analysis calculates the sample size required to detect an effect of a given size with a specified probability.
Question 2: In Design of Experiments (DOE), what is a 'confounded' effect?
- An effect that is statistically insignificant
- An effect whose estimate is mixed with another effect due to the design structure (Correct answer)
- An effect observed only at high factor levels
- An effect that violates the normality assumption
Correct answer: An effect whose estimate is mixed with another effect due to the design structure
Confounding occurs when the estimate of one effect is aliased with another, making them indistinguishable from each other.
Question 3: What does 'heijunka' refer to in lean process management?
- Continuous improvement through small changes
- Production leveling to smooth workflow and reduce waste (Correct answer)
- Visual management of the shop floor
- Mistake-proofing devices on equipment
Correct answer: Production leveling to smooth workflow and reduce waste
Heijunka is the practice of leveling production volume and mix over time to reduce variability and inventory.
Question 4: When applying regression analysis to process improvement, what does a high VIF (Variance Inflation Factor) indicate?
- Strong model predictability
- High residual autocorrelation
- Multicollinearity among predictor variables (Correct answer)
- Non-constant error variance
Correct answer: Multicollinearity among predictor variables
A VIF greater than 10 typically indicates problematic multicollinearity, where predictors are highly correlated with each other.
Question 5: In a TRIZ problem-solving framework, what is the 'Ideal Final Result' (IFR)?
- The best solution achievable within current budget constraints
- A state where the system performs its function without existing as a physical entity (Correct answer)
- The highest sigma level attained after improvement
- The solution that eliminates the most defects per unit
Correct answer: A state where the system performs its function without existing as a physical entity
The IFR describes the ideal solution where the desired function is achieved with no system, cost, or harm — guiding creative problem solving.
Question 6: Which advanced quality tool maps the sequence of events leading to a failure to identify latent root causes?
- Scatter diagram
- Event and Causal Factor (ECF) chart (Correct answer)
- Run chart
- Affinity diagram
Correct answer: Event and Causal Factor (ECF) chart
An ECF chart links events and causal factors chronologically to expose the chain of conditions that enabled a failure.
Question 7: In the context of process capability, what does a negative Cpk value indicate?
- The process has very low variability
- The process mean is outside the specification limits (Correct answer)
- The process is perfectly centered
- The sample size was insufficient
Correct answer: The process mean is outside the specification limits
A negative Cpk means the process mean has shifted beyond one of the specification limits, producing a large proportion of nonconforming output.
CPS Advanced Techniques & Methods 2
Which statistical tool is used to determine the minimum number of samples needed to detect a process shift of a specified magnitude?