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Guide · data migration

ERP data migration: what to move, what to leave behind

Data migration is the most underestimated phase of an ERP project. It rarely costs much technically, but it often costs a lot of your own time.

This guide shows what we migrate, what stays in the old system, the five-step Odoo import method and the data cleansing to do before the first load. It applies to a data migration from a legacy ERP as much as from spreadsheets.

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The short answer

The sensitive point is not the import technique, which is well mastered. It is the quality of what you import. A dirty master data set does not become clean by changing tools: it gets amplified.

What is migrated and what is not

Always

Third parties, products, bills of materials, price lists and open balances: unpaid invoices and stock.

Sometimes

Sales history for statistics and detailed accounting entries depending on your needs.

Almost never

Old, closed documents. We keep the old system available for consultation, which is safer and cheaper.

Data cleansing: why dirty master data costs more than the software

Duplicates, inconsistent units and poorly built product categories are amplified by an ERP. Wrong stock and wrong margins almost always come from there, rarely from the software.

  • customers recorded twice, with different terms;
  • products in kilos in one file and in units in another;
  • obsolete references cluttering the lists;
  • balances that do not reconcile accounting with stock.

Cleaning before importing costs your teams time. That is the time you need to plan for in the schedule.

This work is scoped upstream: during the free situation audit run by our organisation consulting practice, we review a sample of your files and set the migration scope with you. Discover our organisational consulting and process review.

The five-step data migration method

1

Extraction

We retrieve the data from the old tool in usable formats.

2

Cleaning

Your teams fix duplicates, units and categories, using our tools.

3

Test import

We load a sample into a test environment to spot discrepancies.

4

Checks

Your key users verify the data: balances, stock, customer records.

5

Final import

The final load takes place on the cut-over date, with up-to-date balances.

Mistakes to avoid

  • migrating everything on principle, including ten years of history;
  • importing without cleaning, hoping to fix it afterwards;
  • leaving the migration to a single person who also has their daily job;
  • forgetting to set a data freeze date before cut-over;
  • not checking opening balances against accounting.

For a chart of accounts to load quickly, our chart of accounts import module avoids manual entry.

Frequently asked questions about data migration

No. Migrate what you need to work tomorrow: third parties, products, price lists and open balances. Keep closed history in the old system, for consultation.

Your teams, because they know their records. We provide tools to check the files and we verify the result before the import.

Data migration loads data from another tool or from spreadsheets into Odoo. An Odoo migration moves an existing Odoo database to a more recent version: the data follows, it is the custom modules that require work. In a full ERP migration, the two are combined.

Odoo imports CSV or Excel files from each list: contacts, products, price lists, journal entries. The useful work happens beforehand: harmonising columns, units and identifiers, then testing on a sample. For large volumes or links between tables, we use controlled import scripts.

Yes, by importing structured files. The work mostly consists of harmonising them beforehand. See moving from Excel to an ERP.

It depends on the volume and the cleanliness of the data. Allow for your teams' cleaning time in the schedule. See how long an Odoo project takes.

Is your data ready?

A sample is enough to find out. We review it with you in thirty minutes.

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