Volume and Mix Analysis by Customer and Product

Hi All,

I need some guidance on a volume mix analysis that I'm working on. Both are comparing planned vs actuals.

In the attached excel there are 2 scenarios:

1. Volume and mix against each customers which to me is straight forward.
Volume variance is Actual - Planned * Planned Margin.
Mix not sure if I got this right - difference in Margin * Actual volume.

However, this is where things get tricky in Scenario 2.

If i were to now look at the products under customer 1 and break this volume and and mix at a product level, i cannot tie it to the customer vol and mix in scenario 1.
in Scenario 2, the total volume and margin for both plan and actual by product is the same as scenario 1.
But if you look at the total volume mix, i'm getting 1.28 for volume, vs .875 for mix.

Intuitively the customer vol variance makes sense and it's easier to explain since people doing mental math can relate. However, not being able to tie total customer vs product breakdown is causing an issue. Hoping someone here might be able to help.

Thanks!