In Excel (and other Office Documents) did you know you can mark your workbook as Final?.  If you have finished work on your workbook, you can discourage any further editing by users by using this feature.

To mark an Excel document as Final in Excel 2013

• Hit File to open the Backstage View
• In the Info Pane- Protect Workbook- Mark As Final

• A dialog box appears as a warning
• Another dialog box appears for confirmation

• The workbook is now marked as read only and warning the user that another user has marked the workbook as Final.
• This only prevents users going straight ahead and editing the document as they have to confirm they wish to go ahead and ‘Edit Anyway’ even though the document has been marked as final

note
The Mark As Final status does not  prevent people from editing the document if they really want to.  You can use the Restrict Access option or the Protect Workbook- Protect Worksheet in the Changes Group of the View Tab to further protection.