The Single-Point-of-Failure Map

If three specific people quit tomorrow, we would be in trouble: [TEAM LIST WITH ROLES, WHAT ONLY ONE PERSON KNOWS HOW TO DO]. Map it: every critical task or system with exactly one human who can run it, ranked by blast radius (what breaks in a day vs a month). For the top five, the cheapest fix - documentation, cross-training, or a backup vendor - with the hours each fix takes. Then the standing rule that stops new single points from forming.