So I have two coworkers who I want to help out with a problem. They have to collaborate on upgrades in a old factory, and they both use the same excel spreadsheet to keep track of the to-do list.

However. This will routinely cause one of them to lose all their work for the day when the other person forgets to close the spreadsheet after doing something.

They are great people. But computers are not their strength. So just reminding them to never start working before checking if the other person is done will not really work. And I always gets asked to help out since I know the basics of excel at least.

So is there anything that can be used for project management, and that has real time collaboration. And can be learned to two people who dislike computers in general.