Enterprise ERP migration from Odoo 16 to Odoo 19

The migration from Odoo v16 to v19 is a large-scale project I led single-handedly at 1UP Distribution. The ERP is directly used by 19 internal users and affects around 30 employees overall through Odoo, logistics, the B2B site, the corporate site, and related workflows.

The main objective was to migrate the entire ERP to Odoo v19 without data loss and with minimal functional regression. The identified risks were significant: potential data loss, incompatible custom modules, unversioned Studio customizations likely to break, and downtime to minimize to avoid impacting business operations.

I started by listing existing customizations: 16 custom modules I built from scratch, about 10 third-party modules to fix, improve, or migrate, and hundreds of customizations made through Odoo Studio.

I worked on a realistic Odoo.sh staging environment based on production data. The switch to Odoo 19 happened on February 6, 2026, and the stable version was reached around 1 month later.

Two important incidents were also resolved during stabilization: recovery of mobile numbers removed by an Odoo change through migration scripts and cron jobs; recovery and reliability improvements for invoice margins through my dedicated module, making margin more reliable than before and fully automated.

I handled the entire technical side of the migration alone. My main interactions were with a colleague, the executive assistant, who knows the ERP very well at a functional level and understands the company's internal processes. Her business knowledge was invaluable for validating that migrated features matched actual usage.

The migration took 6 months of preparation and the main post-switch stabilization lasted around 1 month. It secured an ERP directly used by 19 users, with 16 custom modules, about 10 third-party modules adapted, and several data incidents resolved. Odoo automations and workflow simplifications save users several minutes to several hours per day depending on the process.

Today, the ERP runs stably on Odoo v19. Users benefit from the new version's improvements and custom modules have been adapted. This migration also laid the groundwork for future updates, which will be simpler thanks to the documentation and migration scripts created during the process.

If I had to do it again, I would more rigorously map the list of changes between versions and the business processes to test, to have fewer unexpected regressions after migration. A more structured acceptance document, validated with key users before the switch, would have further reduced the number of post-migration fixes.