Lean Six Sigma Green Belt Certification DMAIC: Improve and Control 5

Question 1

A team finds that its process average has shifted by 1.5 sigma over time. According to Lean Six Sigma convention, how does this assumption affect the reported DPMO for a Six Sigma process?

Accepted Answer

DPMO increases from near zero to 3.4

Answer

DPMO increases from 3.4 to 233

Answer

DPMO decreases because the shift is accounted for in Ppk

Answer

DPMO is unaffected because it is based on Cpk, not the mean

Question 2

Which type of waste in Lean is represented by producing goods before customer demand requires them?

Accepted Answer

Overproduction

Answer

Defects

Answer

Waiting

Answer

Excess inventory

Question 3

A team conducting a pilot test records these cycle times (seconds): 42, 45, 44, 43, 46, 44, 45. The spec limit is 50 seconds maximum. What is the most accurate statement?

Accepted Answer

The process appears capable, but a full capability study with more data is needed to confirm

Answer

The process is not capable because the mean exceeds the upper spec limit

Answer

The process is Six Sigma capable based on this data

Answer

The process is out of control and needs corrective action

Question 4

Which response surface design is most efficient for estimating a full second-order (quadratic) model with three factors?

Accepted Answer

Box-Behnken design

Answer

Full 2^3 factorial

Answer

Plackett-Burman design

Answer

Fractional 2^3-1 design

Question 5

A control plan specifies a reaction plan of 'call supervisor.' Which improvement would make this reaction plan most effective?

Accepted Answer

Add specific, time-bound criteria for when to escalate and what containment action to take immediately

Answer

Replace it with 'notify quality department via email'

Answer

Remove it and rely on operator judgment

Answer

Link it to the SIPOC diagram for traceability

Question 6

After implementing a process improvement, the team updates the control chart and notices that the new control limits are significantly narrower than the old ones. What does this indicate?

Accepted Answer

Process variability has been reduced by the improvement

Answer

The measurement system has deteriorated

Answer

The process has become less stable

Answer

The subgroup size was incorrectly changed

Question 7

A project's improvements are implemented but the process owner is resistant to maintaining the changes. What is the most effective long-term strategy?

Accepted Answer

Automate or mistake-proof the improvement so it is built into the process itself

Answer

Escalate to the sponsor to mandate compliance

Answer

Schedule monthly audits by the Green Belt indefinitely

Answer

Archive the control plan and close the project