On-call
GlossaryWritten by Burak YEditorial review by Burak YLast editorial review 3 September 2026
An operating model that assigns reachable responsibility for systems requiring human response. A complete on-call system is more than a rota: it combines ownership, schedules, alert routing, notification channels, escalation, runbooks and a way of learning after incidents. Any one of those missing tends to show up as a missed or delayed response.
In practice
A two-person team without a written escalation path technically has on-call coverage. In practice, when the primary's phone is silent, nothing happens next.