What’s A Levene’s Test?

Levene’s Test is a hypothesis test that determines whether a statistically significant difference exists between the variance of two or more independent sets of non-normally distributed continuous data. It is useful for determining if a particular strata or group could provide insight into the root cause of process issues.

An example would be if Assembly Line A has cycle times with a variance of 2 minutes where as Assembly Line B has cycle times with a variance of 3 minutes and you want to determine if Line A truly has less variation or if the difference is just due to random chance.

Learn more about Levene’s Tests in Analyze Phase, Module 4.4.1 of Black Belt Training.

How To Run A Levene’s Test In SigmaXL

Download the GoLeanSixSigma.com Levene’s Test Data Set for SigmaXL here.

1. Select Raw Data:

Levene'sTest-SigmaXL-RawData

 

2. Go to Statistical Tools > Equal Variance Tests > Levene >:

Levene'sTest-SigmaXL-SelectData

3. Click Next:

Levene'sTest-SigmaXL-Settings

4. Click Stacked Column Format. Highlight Total Order Lead Time and click “Numeric Data Variable.” Highlight Weekday vs Weekend, and click on “Group Category”

5. Click OK:

Levene'sTest-SigmaXL

To learn more about Levene’s Tests, register for Black Belt Training and review Analyze Phase, Module 4.4.1.