You can save any modification during work, including during a network problem. The other users know that you are performing some modifications nevertheless, no one else can do some modifications at the same time. Before Check-In, it is still possible to cancel the modifications using "Undo Check- Out" command. You are also able to delete the Checked Out Documents in SmarTeam.

In order to know more about this operation, please check out the document below.

More: Which are the different way to perform a Check-Out operation, for which usage?