When inventory is received the receiving process executes a procedure that scans the open sales orders for the item received and allocates the newly received inventory to those sales orders waiting for the items. This whole process can be disabled to eliminate allocation on receiving (set IRALLOVL to “(blank)”), or it can be controlled by setting the auto-allocate flag in the inventory master for specific items. The receiving allocation process also checks if the item being received completes any “kits” waiting for parts.
If the Purchase Order line being received was created with a link to a sales order the goods received are first allocated to that sales order and the remainder according to the normal allocation sequence
Inventory Allocation - Night Time Processing