If you manage chromebooks (or other ChromeOS devices) in a Google Apps for Education or Google Apps for Work system, you need this tool.
The Chromebook Inventory Add-On for Google Sheets allows you to quickly make a spreasheet of your managed chromebooks. You can then edits the spreadsheet and export it back to the Google servers. When the export is done, it will update those settings. This makes it a convenient tool to do bulk updates, move large numbers of chromebooks to a new OU, make inventory files, or make checklists.
I couldn't explain this system any better than the seven minute long video that they provide. So just check that out.