DMAIC: Improve and Control Flashcards
7 cards from real Lean Six Sigma Green 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 7 DMAIC: Improve and Control flashcards as text
A Green Belt team has identified three potential solutions with similar cost. Which technique best prioritizes them based on impact versus effort?
Answer: Pugh concept selection matrix
A Pugh concept selection matrix scores competing solutions against weighted criteria such as impact, cost, and feasibility to guide selection.
During a pilot run of a new process, the team observes that output variability decreased but the mean shifted away from target. What is the most likely next step?
Answer: Adjust process settings to re-center the mean while preserving reduced variability
When a pilot reduces variability but shifts the mean, the team should tune the control factors (e.g., setpoints) to re-center output without sacrificing the variability gains.
Which type of mistake-proofing device physically prevents a defect from being passed to the next step?
Answer: Detection poka-yoke
A detection poka-yoke identifies a defect after it occurs and prevents it from moving forward, while a control (prevention) poka-yoke stops the defect from being made at all.
A control chart shows a process in statistical control, but customer complaints persist. What should the team investigate first?
Answer: Check whether the control chart specifications match customer requirements
A process can be statistically stable yet still fail to meet customer specs if the control limits were set without reference to specification limits.
In Design of Experiments, what does 'confounding' mean?
Answer: The effect of one factor cannot be separated from the effect of another
Confounding occurs in fractional factorial designs when the effects of two or more factors or interactions are aliased, making it impossible to distinguish their individual contributions.
What is the primary purpose of a pre-control chart in the Control phase?
Answer: To provide a simple, specification-based method for operators to detect process shifts
Pre-control uses zones based on specification limits to give operators a straightforward signal to stop and adjust before defects are produced.
A team completes the Improve phase and hands off to operations. Which document is most critical to ensure the improvement is sustained?
Answer: Control plan
The control plan documents what to measure, how often, who is responsible, and what actions to take when out-of-control conditions occur, making it the anchor for sustaining improvements.