Ironically, I have a good solution that I use for Access databases, including
a custom form with a timer that kicks a user out after they are idle for a
while, but saves their changes and provides the option to re-do those changes
when the user comes back. However, that solution is a little too complex for
this situation.
Dave, I understand your concerns, but if the workbook is not shared, and
some user has it opened and decides to take an extra long lunch, or even a
vacation, then everyone else who requires access to the workbook is impacted.
It is unacceptable one inconsiderate user to impact a whole organization.
What about the suggestion to make the workbook shared? When you do that,
multiple users can open and edit the file at the same time. Also, you have
access to a change history log so you can see who has been editing the file
over time. Finally, when you share a workbook, the users are prevented from
making structural changes to the workbook. They can't do things like
add/delete sheets or make formatting changes. The only way to make that kind
of change is to "unshare" the workbook, make the changes, and then share it
out again.
Tools/Share Workbook...
Check the "Allow changes by more than one user at the same time." box.
HTH,
Eric