* In Admin Console:
# go to {nav Website & Content > Structure & Data > Products} section
# create 4 products
# for all of them enable inventory tracking `By Product` (on the `Inventory` tab during product editing)
# for 2 of them add 10 to the stock (on the `Inventory` tab during product editing)
# go to {nav Configuration > E-Commerce > Shipping} section
# create new shipping type with following configuration:
* [General Tab] Shipping Type = handling
* [Shipping Zones Tab] Add new zone, that will contain all countries
* [Brackets Tab] Press the "Infinity" toolbar button
# go to {nav Configuration > E-commerce > Payment Types}
# enable `Check/MO` payment type and make it primary
* On Front End:
# login
# add qty=1 of each product to cart
# perform checkout and select, that you want all items shipped together
# in Admin Console confirm, that
* order in `Pending` status was created
* approve the order
* confirm that order status was changed to `Backorders`
# perform checkout and select, that you want backorderdered items shipped separately
# in Admin Console confirm, that
* order in `Pending` status was created
* approve the order
* confirm that order was split into 2 orders where one has `To Ship` and other has `Backorders` status