Decision authority

Somebody has to be allowed, in advance, to take drastic action. Isolate the network, take a customer-facing service down, stop a production line.

If that authority has not been agreed beforehand, the first hour of a serious incident is spent finding somebody senior enough to approve it, at exactly the point when hours are expensive. The technical work is rarely what delays a response. Waiting for permission is, and it is entirely avoidable by deciding once, in writing, who can make the call.