To begin with, this is a rather technical post and not an easy read. So you should only go through it if you came across the problem and have a need to solve it. OK, let’s get to it.
Say you have a total margin of 40% and last year that was 30%. You want to show to which elements the +10% change is attributable to by breaking down the variance into effects. The challenge here is the complexity coming from having changes in absolute and margin %, changes in product mix and changes in revenue all baked into the margin % variance.