Lean Six Sigma Green Belt Certification Control Phase and Sustainment 2

Question 1

A Green Belt notices a control chart with a run of 8 consecutive points above the centerline. What action should be taken?

Accepted Answer

Investigate for a special cause even though limits are not breached

Answer

Eight consecutive points on one side of the centerline is a non-random pattern (Western Electric Rule) indicating a special cause that requires investigation regardless of control limit violations.

Question 2

Which document is MOST effective for ensuring operators consistently follow a newly optimized process?

Accepted Answer

Standard Operating Procedure (SOP)

Answer

A Standard Operating Procedure (SOP) provides step-by-step instructions that standardize how operators perform tasks, directly supporting process sustainment.

Question 3

During a control plan review, the team finds that a CTQ characteristic has a Cpk of 0.85. What does this indicate?

Accepted Answer

The process is not capable and is producing defects

Answer

A Cpk below 1.0 indicates the process is not capable of consistently meeting specifications and is likely producing defects or out-of-spec output.

Question 4

What is the PRIMARY purpose of a response plan within a control plan?

Accepted Answer

To describe corrective actions when a process goes out of control

Answer

A response plan specifies the corrective actions operators and supervisors should take when a control chart signals an out-of-control condition.

Question 5

A team implementing statistical process control (SPC) should establish control limits using data from:

Accepted Answer

A period when the process was known to be stable and in control

Answer

Control limits must be calculated from historical data collected when the process was stable, so they reflect natural process variation rather than specification requirements.

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification Control Phase and Sustainment 2