Online allocation
If your company is setup to use the online allocation method, items are allocated as each customer order is added. Online allocation reserves items on a first come, first served basis.
If insufficient stock exists to fulfill all orders, then you can use online allocation forms to choose which orders to fill, whether or not you are set up to use online allocation. However, there is a small window of time during which you can maintain allocations online -- before pick tickets are printed. See Online allocation.
Whether you are set up to use online or batch allocation normally, you can use batch allocation to allocate backordered item quantities. Also, you can deallocate quantities using the batch program.