If you have and Staff that have become inactive, then you can disable them in the Web app.
Disabling a Staff member means that any Ops that are assigned to that Staff will not be considered Due/Overdue/Missed; However, any Ops or Issues that were actioned before the Staff member was disabled will still exist in Reporting and the Issues Log.
If the Staff member tries to sign in after being disabled, then they will receive an error that will notify them that they are no longer active and need to contact an Admin of their account.
To disable Staff:
Navigate to the Staff area in the Web app
Select the Staff member that is no longer active
Use the toggle to the right of the Staff member you would like to disable, and switch it to the off position (it will appear grey, rather than green)
Your Staff is now disabled