Lean Six Sigma Green Belt Control Phase and Sustainment Questions and Answers

Question 1

What is the primary purpose of the Control Phase in a DMAIC project?

Accepted Answer

To lock in the gains and ensure the improved process is sustained.

Answer

To identify the root causes of process variation using statistical tools.

Answer

To brainstorm and implement a wide range of potential solutions.

Answer

To validate the measurement system's accuracy and reliability.

Question 2

A project team implemented a new stocking procedure to reduce order fulfillment time. To monitor the new process and ensure it remains stable, they track the average fulfillment time daily. Which tool is most appropriate for this task?

Accepted Answer

Statistical Process Control (SPC) Chart

Answer

Fishbone Diagram

Answer

Pareto Chart

Answer

Failure Mode and Effects Analysis (FMEA)

Question 3

Which of the following is the MOST critical component of a comprehensive Control Plan?

Accepted Answer

A response plan for out-of-control conditions.

Answer

A list of all team members and stakeholders.

Answer

The initial process capability analysis from the Measure phase.

Answer

A detailed summary of the brainstorming sessions from the Improve phase.

Question 4

A Green Belt project to reduce invoicing errors has successfully concluded, and the improved process is stable. What is the final, crucial step to ensure long-term sustainment of the gains?

Accepted Answer

Formally transferring ownership to the process owner with a documented control plan.

Answer

Recalculating the project's ROI for the final presentation.

Answer

Conducting one final Design of Experiments to re-verify the results.

Answer

Writing a press release to celebrate the project's success.

Question 5

A manufacturing team has implemented a new assembly sequence that is more ergonomic and efficient. To ensure all operators, including new hires, perform the task consistently according to the improved method, what document should be created or updated?

Accepted Answer

Standard Operating Procedures (SOPs)

Answer

A project storyboard

Answer

A stakeholder analysis

Answer

A Pugh matrix

Question 6

An X-bar and R chart is being used to monitor the average diameter of a machined part. The process owner observes six consecutive points trending downwards, but all points are still within the control limits. According to standard SPC rules, what is the correct interpretation?

Accepted Answer

This pattern indicates a special cause of variation that should be investigated.

Answer

The process is perfectly stable and requires no action.

Answer

The control limits should be immediately recalculated based on the new trend.

Answer

The measurement system is likely broken and must be replaced.