Lean Six Sigma Yellow Belt Certification The Control Phase 2

Question 1

What is the primary purpose of a control chart in the Control phase?

Accepted Answer

To monitor process performance over time and detect special cause variation

Answer

Control charts monitor process performance over time, distinguishing between common cause and special cause variation.

Question 2

Which of the following best describes 'common cause variation'?

Accepted Answer

Natural, inherent variation present in every process

Answer

Common cause variation is the natural, random variation inherent in a stable process and does not require special intervention.

Question 3

A control plan is created during the Control phase. What is its main function?

Accepted Answer

To document how the process improvements will be sustained over time

Answer

A control plan documents the methods, responsibilities, and monitoring activities needed to sustain process improvements.

Question 4

In a control chart, what does a data point outside the upper or lower control limit indicate?

Accepted Answer

Special cause variation requiring investigation

Answer

A point outside control limits signals special cause variation, indicating an unusual event that should be investigated.

Question 5

What does 'mistake-proofing' (poka-yoke) aim to achieve in the Control phase?

Accepted Answer

Preventing defects by making errors impossible or immediately detectable

Answer

Poka-yoke devices or methods prevent errors from occurring or detect them immediately so they cannot become defects.

Lean Six Sigma Yellow Belt Certification Practice Test