GATP allocate the batch to sales order when confirmed?

[road2sap]

We are working on a project to search the batch according to self life when doing the ATP check in GATP, but we got a question here:

for example:
1. sales order 1000001, require 100 Carton of material A.
Stock:
A batch_1 50 self life: 100 days
A batch_2 100 self life: 80 days
A batch_3 100 self life: 60 days
A batch_4 100 self life: 50 days

when doing the first ATP run, accoridng to first expire first out, it found batch_1 and batch_2, and get 50 from batch_1, 50 from batch_2 -> order 1000001 confirmed

2. next hour, another sales order 1000002 coming in, when doing GATP check for sales order 1000002, if it will consider batch_1?

We want to know GATP lock the batch which allocates to confirmed sales order?

much apprecaite,

[road2sap]

any idea?