If a customer adds something to their cart but then leaves your site without coming back, you'll be left with an abandoned order in Simple Commerce.
However, you may wish to delete orders that have been abandoned. Simple Commerce provides a command to delete abandoned carts/orders that were created more than 14 days ago.
You may setup the command so it's run on a regular schedule. Simply add it to your app/Console/Kernel.php
For more documentation on scheduling, please review the Laravel documentation.