Lean Six Sigma Green Belt Certification LSSGB 1

Question 1

When a data point falls outside the control limits on an X-bar control chart, this most likely indicates:

Accepted Answer

A special cause of variation has entered the process

Answer

Points outside control limits signal special (assignable) cause variation — an unusual event or shift not inherent to the process. Common cause variation, by definition, keeps points within the limits. The correct response is to investigate and eliminate the special cause before drawing conclusions about capability.

Question 2

In Lean, 'takt time' is defined as:

Accepted Answer

The available production time divided by customer demand rate

Answer

Takt time (from German 'beat') sets the production pace required to meet customer demand. It is calculated as Available Production Time ÷ Customer Demand. It serves as the heartbeat that synchronizes process output to pull — not a measure of actual cycle time or lead time.

Question 3

Which of the following is NOT one of the eight wastes in Lean manufacturing (DOWNTIME)?

Accepted Answer

Inspection

Answer

The 8 Lean wastes (DOWNTIME) are: Defects, Overproduction, Waiting, Non-utilized talent, Transportation, Inventory, Motion, and Extra-processing. Inspection is not a standalone named waste — though it may be a symptom of defects or over-processing, it does not appear as one of the eight categories.

Question 4

In a Gauge R&R (Measurement System Analysis) study, 'Reproducibility' specifically quantifies:

Accepted Answer

Variation that arises when different operators measure the same part with the same gauge

Answer

Reproducibility captures operator-to-operator variation — how consistently different people obtain the same reading on the same part with the same instrument. Repeatability, by contrast, is instrument variation from a single operator. Distinguishing the two guides whether to address the tool or the people/training.

Question 5

In inferential statistics, what is the correct interpretation when a Six Sigma team rejects the null hypothesis?

Accepted Answer

The sample data provides sufficient evidence that the null hypothesis is unlikely to be true

Answer

Rejecting the null hypothesis means the observed data would be very unlikely if H₀ were true (p ≤ alpha), so the team concludes there is sufficient statistical evidence against it. It does not 'prove' the alternative — it simply means H₀ is implausible given the data. Rejection occurs when p ≤ alpha, not p > alpha.

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification Practice Test

Lean Six Sigma Green Belt Certification LSSGB 1