Hi,
Not sure if this is the best section for it but here it goes.
Traditionally we have broken up our year over year changes into two parts, a volume and a price variance. Those variances then add up to the total variance. The current forumula’s I have for them are
volume Variance =( ( [volume this year] - [volume last year] ) * [price last year] ) / [revenue last year]
price variance = ( ( [price this year] - [price last year] ) *[volume this year] ) / [revenue last year]
But what I realized is that this gives a false picture because the number of selling days (week days) differs.
So what I think I need is something like
Volume variance = [volume per sales day this year] – [volume per sales day last year] ) * [price last year] ) / [revenue last year]
price variance = ( ( [price this year] - [price last year] ) *[volume this year] ) / [revenue last year]
but the numbers don’t look right. I think I probably need a third piece something like
variance due to number of days = [average volume per day this year ] / [volume last year]
or something like that but I’m not quite sure. Before everything added up real nice.
Thoughts?