Move from the platform being used to the platform being relied upon, and retire the parallel spreadsheets.
Define match rules, tolerances, reconciliation templates, approval matrices, risk classifications and the close calendar.
Move account inventories, open reconciling items, schedules and retained evidence from spreadsheets and legacy systems into the platform.
Establish what exists today: entities, ERPs, account inventories, current reconciliation practice, and which of it is documented anywhere.
Cut over to the platform as the system of record for the in-scope process.
Intensive support through the first one to three close cycles, correcting configuration as real conditions surface.
Connect ERPs, banks, card processors and other source systems, and establish the ingestion schedule.
Run the new process alongside the existing one for one or two close cycles and reconcile the differences.
Have the finance team who will use it confirm the configuration produces correct and workable results.