In REF to Shared network drive with Office and delete permissions disabled leads to not being able to save
We have several businesses that are now pushing over 30+ employees and many of these employees come and go. In some cases they delete files and we are forced to restore files and entire shared drives.
How are bigger organizations handling file management and preventing files from being deleted by employees?
It's called backups, and VSS/Previous Versions. If needed, implement an actual document management system with versioning and auditing.
Existing employees usually have a lot of motivation to not delete files. First, they want to be able to use their files on a day to day basis, and deleting them won't help with that. Also for existing employees, inappropriately deleting files should cause them to become former employees at some point. As mfinni points out, Shadow Copies AKA Previous Versions is a great tool for taking care of accidental deletions. Most users learn to self-service on Shadow Copies so IT doesn't even know there was an accidental deletion.
Former employees should not even know they are former employees until after or around the same time their access to everything is revoked. That way they can't sabotage files on their way out the door.