Operation and split confirmation - Individual capacities

Hi Experts, appreciate if you could please clear some stuff here for me..

I have a requirement to work with operation splits. Just to keep it simple, I will take a easy example

Lets say I have an operation 0010 and I created just 1 split for this because I just have one individual capacity.

operation 0010 - start date dec 1 and end date dec 2

capacity requirements generated = 48 hrs

I created a split

split 1 - start date dec 3

capacity requirements = 48 hrs

if I dispatch operation 0010, it consumes 48 hrs of the capacity from dec 1 to dec 2

If I dispatch split 1, it consumes 48 hrs of the capacity from dec 3 to dec 4

but my real capacity is just 48 hrs, in the above example I am filling up 2 * 48 hrs which is incorrect, because for other production order, the capacity will be shown as overload..

so  where am I am wrong conceptually?