Koha allows for handling temporary locations like the processing center and/or book carts throughout the library. For this feature to work you must first make sure you have authorized values set in the LOC category for PROC (Processing Center) and CART (Book Cart).

Next you need to set the NewItemsDefaultLocation system preference to PROC. This will set the new items to the Processing Center as their default location.
Create items with their desired final shelving location.
These newly cataloged items will be temporarily set to the PROC location and will display with whatever description PROC has. The original location code entered at item creation is stored in the new items column 'permanent_location', for future use. Items will stay in the PROC location until they are checked in. To have those items then move to the shelving cart:
Turn on the InProcessingToShelvingCart system preference
Check in those newly-created items and they will be moved to the location code of CART and display with whatever description CART has.
A cron job runs at specified intervals to age items from CART to the permanent shelving location. (For example, an hourly cron entry of cart_to_shelf.pl --hours 3 where --hours is the amount of time an item should spend on the cart before aging to its permanent location.)
If the ReturnToShelvingCart system preference is turned on, any newly checked-in item is also automatically put into the shelving cart, to be covered by the same script run.
Checkins with confirmed holds will not go into the shelving cart. If items on the shelving cart are checked out, the cart location will be cleared.