Lean Six Sigma Yellow Belt Certification Statistical Thinking and Variation 1

Question 1

What are the two main types of process variation recognized in Six Sigma?

Accepted Answer

Common cause and special cause variation

Answer

Six Sigma distinguishes between common cause variation (inherent to the system) and special cause variation (assignable to a specific, identifiable factor).

Question 2

Which of the following is an example of special cause variation?

Accepted Answer

A damaged cutting tool producing oversized parts

Answer

A damaged cutting tool is a specific, identifiable event causing variation beyond the process baseline, making it a special (assignable) cause.

Question 3

Walter Shewhart's primary contribution to statistical thinking was developing a method to:

Accepted Answer

Distinguish between common and special cause variation

Answer

Shewhart developed Statistical Process Control and control charts specifically to help practitioners differentiate between common cause and special cause variation.

Question 4

A process that exhibits only common cause variation is described as:

Accepted Answer

In a state of statistical control

Answer

A process with only common cause variation is stable and predictable — it is said to be in a state of statistical control.

Question 5

Statistical thinking in Six Sigma is best described as:

Accepted Answer

Recognizing that variation exists in all processes and can be measured and reduced

Answer

Statistical thinking is a framework that acknowledges variation is inherent in all processes and that data-driven analysis is the key to understanding and improving them.

Lean Six Sigma Yellow Belt Certification Practice Test

Lean Six Sigma Yellow Belt Certification Practice Test

Lean Six Sigma Yellow Belt Certification Statistical Thinking and Variation 1