Summing up different granularitys

Hello!

I am looking for a function/ approch for summing up the value on the lowest granularity for a whole family.

So, I have an ItemMaster like this:

Then I have a Fact Sheet with the Value per Article per Day

And then I have a table with the Budget per Article (Article-Budget)

Now I want to calculate the difference between the Target and the Value per Item per Week.

This can be solved by an easy subtraction like [Target]-[Value].

Now I want to calculate the sum of all article per area, that are below Target.

And then I want to calculate the sum of all articles that are above Target.

How would you do that with a Dax Measure?