gATP not taking into account temporary quantities correctly when batch managed material

[edsays73]

Hi All.

I have a particular situation with gATP that I need the collective wisdom of the APO experts in this community to help sort out.

I have a batch managed material A with product substitution, 8 units stock in the original material. The following screen is shows basically what co09 does. The 8 in the column EXI… is the ATP quantity

I make a sales order for 2 of that material but I don’t save the order and leave it open

When I go to check the temporary quantity assignments, I see that order is reserving 2 units and negative 50 (I don’t know what negative quantities mean in this context)

Now I go back to VA01 and create another order for 7 units without closing the first one.

What I expect to see in the above sales order is, as there is not enough stock in any of the locations, the substitute product should have been used

If I look at the TQA again we see the following:

Now if I change the quantity in the order to 9 units then the substitute material is added in correctly

The TQA also correctly reflect the quantities

I don’t understand why this is working this way. If I try this same exercise with a non-batch managed material gatp works as expected.

Any help would be greatly appreciated.