Lean Six Sigma Yellow Belt The Control Phase Questions and Answers

Question 1

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

Accepted Answer

To sustain the gains achieved and ensure the process does not revert to its old state.

Answer

The Control Phase is focused on maintaining the improvements made in the Improve phase. It involves creating monitoring systems and standardizing procedures to ensure the gains are sustainable over the long term and the process remains stable.

Question 2

A team has successfully reduced defects in a production line. To monitor the process going forward, they plot the number of defects per week on a chart with a center line and statistically determined upper and lower limits. What is this tool called?

Accepted Answer

Control Chart

Answer

A Control Chart (a form of Statistical Process Control or SPC) is the primary tool used in the Control Phase to monitor process performance over time. It helps distinguish between normal, expected variation (common cause) and unusual events that need investigation (special cause).

Question 3

Which of the following is a key deliverable created during the Control Phase that documents how to maintain the improved process performance?

Accepted Answer

A Control Plan detailing monitoring actions and response procedures.

Answer

The Control Plan is a comprehensive document created in the Control Phase. It specifies the metrics to be monitored, the methods and frequency of measurement, and the reaction plan to follow if the process goes out of control, ensuring the improvements are maintained.

Question 4

On a control chart used to monitor a process, a single data point is observed to be above the Upper Control Limit (UCL). What does this signify?

Accepted Answer

The presence of special cause variation.

Answer

Data points that fall outside the control limits (UCL or LCL) are statistical signals that an unusual, non-random event has occurred. This is known as special cause variation and requires investigation to understand and address the source.

Question 5

A project team has implemented a new, more efficient method for processing invoices. To ensure all employees use the new method consistently, they update the official work instructions and conduct training sessions. This activity is a crucial part of which Control Phase element?

Accepted Answer

Standardizing the process

Answer

A key part of controlling a new process is standardization. By updating Standard Operating Procedures (SOPs), work instructions, and providing training, the team ensures that the improved method is clearly defined and followed by everyone, reducing variation and sustaining the gains.

Lean Six Sigma Yellow Belt Certification Practice Test

Lean Six Sigma Yellow Belt Certification Practice Test

Lean Six Sigma Yellow Belt The Control Phase Questions and Answers