In my previous PSA I had create workflows to send a 1st notice at 24hours of a ticket being in "Waiting on Client", once no response in 48hrs a 2nd email was sent, after 72 hours it would email and let them know if we had not heard back by COB that day we would be closing the ticket. and would close the case, customer was able to reopen by responding to any of the emails associated..
I am not able to find a way to do this with BMS
Yup, I've got this (mostly) successfully working. You'll need:
1. A "Waiting on Client" ticket status
2. An "Updated by Client" ticket status or equivalent.
3. A workflow for each timed action.
4. One extra workflow to update ticket status.
In your example, there would be a workflow for the 24 hours notice, the 48 hours notice, and the 72 hours notice, and the closure. Each of these should use the "Idle For:" workflow field and should be filtered to tickets in the "Waiting on Client" status. The 24, 48, and 72 hours workflows should just send a templated email to the primary contact of the ticket. The last timed workflow (which closes the ticket) should adjust the ticket status to "Closed" or your equivalent.
Finally, you need a workflow which uses the "Activity Added By:" trigger filtered to "Anyone Except Employees". It needs to modify the status of tickets in "Waiting on Client" to "Updated by Client". That change will exempt the ticket from any remaining closure workflows (and should probably notify the assigned tech). If you don't filter the ticket status, then this will also to re-open closed tickets.
Note that this doesn't handle weekends or holidays at all. The timer will also reset if any change is made to the ticket, so make sure you're careful about changes you make on tickets you want to expire. Also, if BMS is offline during the time when a trigger should fire (for maintenance or an upgrade), then the trigger will be missed. This can lead to tickets that should have been closed and just sit there, so keep an eye on old tickets with the "Waiting on Client" status.
Hopefully this points you in the right direction. Let me know if I can clarify!