What is an on-call roster?
Also called: on-call rota, call roster, duty roster
On-call roster: ordered list of people taking turns being on call for a service, plus the rotation rule deciding whose turn it is.
On-call roster is the ordered list of people who take turns being on call for a service or team, plus the rotation rule that decides whose turn it is. The roster answers who is in the pool and in what order. It contains no dates. Apply a rotation rule, like weekly handover at Monday 09:00, and the schedule is generated.
Three people is the practical minimum for a roster that pages out of hours. Two people is a coverage arrangement that collapses on the first holiday. One roster per distinct area of expertise is better than one per service.
Holidays and swaps are handled with overrides on top of the schedule, so the roster itself only changes when someone joins or leaves.