Final Issue flag on residual quantity in batch determination

Guys,

When we do batch determination, a small quantity is left over in first row. For ex, material X is required as 10 lt. Two batches of of 4,5 lt is assigned. So the remaining quantity is 1 lt. We never produce 1 lt so we should not send this quantity to MRP as requirement. Whats the best way to kill this requirement? Setting Final issue flag through some exit or net requirement calculation change in MRP? etc. Please advise

Cheers

Sunny