How the replenishment rules work to the stores from the warehouse?

Hi,

Wanted to understand the “rules” in place when there is less inventory available than the replenishment demand.

An example of this is we have a demand for 10 units to be distributed at 2 per store between all the stores.  How does it decide what stores will actually get the product (store order ascending/descending, weights, would it ever replenish less per store to give it to more stores (aka 1 each for the first 10 stores versus 2 each for the first 5 stores)).

Believe the program REQEXT does this but would like to know the part of code which performs this.

Thanks,

Karthirenga S