Data migration without the drama

Drama in migration is usually postponed discipline. Mappings start late. Cleansing is assigned to whoever looks least busy. History is migrated because deletion feels like a risk. The first rehearsal is also the first time finance sees the numbers, which means it is not a rehearsal. It is a surprise.

Decide the history window with the people who will be asked questions later: controllers, auditors, and the operator who still needs last year's order. Everyone else is migrating out of anxiety. Archive is a design. Dragging a decade of unused documents into a new ledger is also a design, and a worse one.

Two rehearsals is the minimum we will sign. The first reveals the rules you thought you had. The second is the one that should tie: trial balance, open items, inventory, and the operational documents required on day one. If the second does not tie, the date moves. Moving a date in daylight is cheaper than explaining a ledger in the dark.

Then retire the shadow. A migration that leaves the old extract alive has not finished. Name the file, name the person who must stop using it, and look again in week three.