Data migration is where most Odoo implementations quietly go wrong. The system itself can be configured correctly and the workflows can be well designed but if the underlying data is inaccurate or incomplete none of that matters once go-live arrives. Migration is often treated as a technical task to finish quickly. In reality it deserves the same planning as any other part of the implementation.
The first step is a full data audit before anything is moved. This means reviewing customer records vendor records product catalogs and financial history in the source system and deciding what actually needs to migrate. Not every record from an old system deserves a place in the new one. Duplicate contacts outdated products and years of inactive data often do more harm than good once they are carried forward without review.
Mapping comes next and this is where many mistakes originate. Fields in the old system rarely match Odoo's structure exactly so each field needs a clear mapping decision rather than a best guess during the import. Units of measure currency formats and tax codes are common points of failure since small mismatches here can silently corrupt reports later. This mapping work should be documented not done informally inside someone's head.
Testing the migration in a staging environment is not optional no matter how small the dataset looks. A sample import should be run first and checked record by record against the source system before the full migration happens. This is also the stage to confirm that historical data needed for audits or reporting actually transferred in a usable form rather than just existing somewhere in the database.
The final step is validation after the full migration runs not just after the initial test. Financial totals should reconcile. Inventory counts should match. A handful of transactions should be traced from start to finish to confirm the data behaves correctly inside real workflows. Migration mistakes caught before go-live are minor corrections. The same mistakes caught after go-live become expensive and disruptive to fix.