ASQ Six Sigma Green Belt 4

Question 1

A Green Belt wants to test whether there is a significant difference in mean cycle times between three machine types. Which statistical test is most appropriate?

Accepted Answer

One-way ANOVA

Answer

One-way ANOVA compares means across three or more groups simultaneously, making it appropriate for comparing cycle times among three machine types.

Question 2

What is the purpose of a process capability index (Ppk) as distinct from Cpk?

Accepted Answer

Ppk uses overall process variation while Cpk uses within-subgroup short-term variation

Answer

Ppk uses total (long-term) standard deviation including all sources of variation, while Cpk uses within-subgroup (short-term) variation representing process entitlement.

Question 3

In a control chart, what does an 'out-of-control' signal indicate?

Accepted Answer

A special cause of variation is likely present

Answer

An out-of-control signal on a control chart indicates a statistically unusual pattern suggesting a special (assignable) cause of variation is present.

Question 4

Which lean tool is used to visually map the flow of materials and information to identify waste and non-value-added activities?

Accepted Answer

Value Stream Mapping (VSM)

Answer

Value Stream Mapping creates a visual representation of the entire process flow, highlighting waste, delays, and non-value-added steps that are candidates for elimination.

Question 5

A team applies the 5 Whys technique. What is the main risk of this analysis method?

Accepted Answer

It can lead to different root causes depending on who is asking the questions

Answer

The 5 Whys is vulnerable to subjective bias since different teams may trace different causal chains from the same symptom, potentially reaching different root causes.

ASQ - American Society for Quality Certification Practice Test

ASQ - American Society for Quality Certification Practice Test

ASQ Six Sigma Green Belt 4