DIVIDE (
SUMX (
VALUES ( 'Capacity Plan Measure'[Element Short Desc] ),
[% d'exploitation] * [Prévisions client en actes]
),
[Prévisions client en actes]
)
That's assuming the [Prévisions client en actes] is additive, which it looks like. If it's not, it'll have to be wrapped in the same SUMX in the denominator, too.