delivery quantity

Hello,

I have setted a delivery unit in the material master.

When I do a sale order, the delivery unit is respected, but when I check availability (and the stock is less than the quantity order) the system doesn't give me a multiple of the delivery unit but all the stock. So the delivery has a quantity different from a multiple of delivery unit .

For example:

material A --> delivery unit 50

stock --> 110

quantity order --> 200

confirmed quantity --> the system propose 110

and so the quantity in the delivery is 110.

How can I have in the delivery respected delivery unit automatically?

I want that the quantity in the delivery is 100...

Thanks in advance

GP