Microsoft 365 has a service-wide outage
Email and Teams are down for everyone at once. A plan says how the team stays in contact and which work can simply wait.
One person's account is compromised
The immediate technical response is an administration task. Who tells customers or partners, if anyone needs telling, is a business decision made in advance, not improvised.
A key decision-maker is unreachable
A plan names a backup approver, not just a backup password, for the decisions that can't wait for one specific person to pick up the phone.