The Control Phase Flashcards
7 cards from real Lean Six Sigma Yellow 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 The Control Phase flashcards as text
What is the primary purpose of a control chart in the Control phase?
Answer: To monitor process performance over time and detect special cause variation
Control charts monitor process performance over time, distinguishing between common cause and special cause variation.
Which of the following best describes 'common cause variation'?
Answer: Natural, inherent variation present in every process
Common cause variation is the natural, random variation inherent in a stable process and does not require special intervention.
A control plan is created during the Control phase. What is its main function?
Answer: To document how the process improvements will be sustained over time
A control plan documents the methods, responsibilities, and monitoring activities needed to sustain process improvements.
In a control chart, what does a data point outside the upper or lower control limit indicate?
Answer: Special cause variation requiring investigation
A point outside control limits signals special cause variation, indicating an unusual event that should be investigated.
What does 'mistake-proofing' (poka-yoke) aim to achieve in the Control phase?
Answer: Preventing defects by making errors impossible or immediately detectable
Poka-yoke devices or methods prevent errors from occurring or detect them immediately so they cannot become defects.
Which metric is most commonly used to measure process capability in the Control phase?
Answer: Cp or Cpk
Cp and Cpk measure how well a process fits within its specification limits relative to its natural variation.
What is the recommended response when a control chart signals a special cause?
Answer: Investigate the cause and take corrective action
Special cause signals require investigation to identify and eliminate the root cause to prevent recurrence.