An on-call rotation is simply a schedule that says who handles urgent issues at any given hour, so a critical problem reaches one clearly responsible person instead of a group chat where everyone assumes someone else has it. For a small team you do not need a heavyweight incident platform to do this well. Here is a setup that works.
Decide what actually pages someone
On-call is for issues that cannot wait for the next working day. Be explicit: usually that means your top one or two priority levels, for example urgent and high. Everything else stays in the normal queue and is picked up during business hours. If every ticket pages someone, on-call stops meaning anything.
Keep the rotation small and fair
Pick a rotation length your team can sustain, commonly one week per person, and rotate in a fixed order so everyone can see when their turn comes. For a team of three or four, one week on and two or three weeks off is a humane balance. Write the schedule down where everyone can see it rather than keeping it in one person's head.
Route urgent issues to the person on call, not everyone
The point of a rotation is that the right single person hears about an urgent issue immediately. When a high or urgent ticket is raised, it should notify whoever is on call at that hour, by email and push, so they can act without watching a queue. Broadcasting to the whole team instead just recreates the "someone else will get it" problem.
Cover the gaps and handovers
Two details make or break a rotation. First, decide what happens when a slot has nobody assigned: the cleanest rule is that the previous person keeps covering until the next scheduled handover, so there is never a silent gap. Second, keep a record of who was on call when an incident happened, because schedules change and "who had the pager last Tuesday" is a question you will eventually need to answer.
Make it easy to run
A good on-call setup is mostly clarity: a defined set of priorities that page, a small fair rotation, alerts that reach the one person responsible, and a record of who covered when. The tooling should make that effortless rather than adding process.
GoReportIt has this built in: a 24/7 on-call rotation by priority and category, alerts routed to the person on call, automatic fallback to the previous shift, and a permanent record of who was paged. See the features, or compare GoReportIt to other help desks.