MBRL: return delivery creation split (RLL)

Hello,

I have created and inbound delivery with two items, based on two scheduling agreements (belonging to the same plant, company code and having the same storage location).

The only difference between the item in the Inbound delivery is the Reference document in the Predecessor data tab at item level.

After posting goods receipt, when I create a return delivery via MBRL transaction code using the material document a delivery split occurs (I got 2 outbound deliveries with one item each one with document type RLL).

I checked OSS notes 546668, 840219 and 1149708. Every thing is OK. But after analysis I found out that the root cause of the delivery split is the field VGBEL (Reference document in table LIPS).

So, when I create another inbound delivery with two items and one Reference document and after that create a return delivery MBRL I got one outbound delivery with two items.

Is it the standard behavior of SAP ? If yes, is there any User Exit to avoid the delivery split ?

Thanks in advance.

Maher.