The single gate that stops three crews
A hospital campus we mapped in Chiang Mai had a perfectly documented generator. Fuel was stocked. The test log was current. The service gate used by the contractor sat on a different key ring, held by a security post that closed at 22:00.
Dependency mapping treats gates, keys, and after-hours phones as assets with owners. We write the owner’s name, not a department. Departments do not answer at midnight.
During the tabletop on day four, we ask: if the main road floods, which entrance still reaches the tank farm? If the answer is “we would climb the fence,” the map is unfinished.
Photograph padlocks. Note whether the same padlock appears on a water valve and a fuel compound. Shared hardware is a shared failure when the key is lost.