Equivalence test for different variance

[#1]

Hi, to viewers

I am checking equivalence test for each batch.

Purpose: To answer this question (Each batch's variance is equivalent?)

Question:

1. What is the meaning of "Margin and Alpha" when selecting the ratio of the standard deviations?
2. It is indicated into "specific practical equivalence interval". Then, how can I set reasonable interval value because equivalence count depends on this margin set?

Thanks! 

[#2]

I checked for you and found some information that might help.

I hope this information is helpful to you. Please note that I'm not an expert with JMP, but I wanted to provide some assistance while one of our experts reviews your message and gets back to you.

Margin and Alpha

Defines the significance levels for the test.

Difference

(Available only for tests for risk difference.) Specifies the equivalence, superiority, or noninferiority margin. This margin, or delta, is the difference that has practical significance. For equivalence tests, the difference must be greater than zero.

Ratio

(Available only for tests for relative risk.) Specifies the equivalence, superiority, or noninferiority margin as a risk ratio. This margin, or delta, defines a risk ratio that has practical significance. The range of values is defined as (Ratio, 1/Ratio). For equivalence tests, the ratio must be different from 1.

Alpha

Specifies the significance level for the test.

chech this link for more information :
https://www.jmp.com/support/help/en/18.0/index.shtml#page/jmp/equivalence-test-reports-2.shtml

This link too:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=video&cd=&cad=rja&uact=8&ved=2ahUKEwilqtiOyuC... 

[#3]

It sounds like you might be looking for the equivalence of means.

Equivalence of means is used for population comparisons. For Example, I have some historical batches and some batches from a new CDMO site. Are the CQA's for the batches equivalent?

The equivalence of variance is often used for determining if the variance between measurement methods is the same. For example, I used a titration method to measure the concentration of an API, and now I'm using an HPLC method. The new system is fit for use, can I determine if the variation is equivalent (or, non-inferior)?