Day-One evidence maps that do not collapse by week three
Most Day-One maps are screenshots of a system inventory slide. They look complete in the kickoff room and become fiction once the first application is switched off. For teams running a financial auditing app for merger integration audit tracking, the map has to answer a colder question: can someone reconstruct this balance after the person who knew the export path has left?
Three columns that matter
We teach learners to keep the map ruthlessly narrow. Every row needs a source system, a named owner still employed, and a retention or export rule that survives cutover. Optional columns for “notes” are where maps die—people hide unresolved ownership there until fieldwork.
If an owner is a vendor contact, write the contract reference and the internal sponsor. If the export is a one-off script, store the script hash and who can rerun it. Fancy diagrams can wait.
Week-three stress test
In Continuity Desk clinics we ask a volunteer to pick a balance at random and walk the map cold. When the walk fails, the fix is usually not more documentation—it is a missing owner or a system that was never on the Day-One list because it only feeds a subledger.
Repeat that stress test after every major cutover. The map is a living control, not a commemorative slide.