An on-call schedule rotates the responsibility through a team, often weekly, with a handover at a fixed time. Overrides cover holidays and sick days, and an escalation policy brings in someone else when the person on call doesn’t respond.
Good on-call depends on the alerts: each page should be urgent, actionable and rare. A rotation in which people are woken for things that can wait until morning wears people out and teaches them to ignore alerts; that is alert fatigue.
Runbooks, clear ownership and time off after a rough night keep a rotation sustainable.