Odoo ERP · Migration
Replacing Homegrown Software with Odoo
· Updated · 2 min read
Homegrown software is hard to leave because one screen hides a rule nobody has written down. The replacement works when you extract the rule and drop the screen.
List the documents, not the menus
Write the documents the business cannot run without: the order, the receipt, the bill, the job. For each one, write the rule the old screen enforces. That list is the first release. The menus nobody opened last month are not.
A field that exists because a developer added it in 2016 is not a requirement until someone uses it on a real document this month.
Rebuild the exception, configure the rest
Standard Odoo should cover the common document. Custom code is for the rule that would otherwise force a side file. That test is in when to customise. Copying every old screen is how the new system becomes the old one, with a licence.
Opening balances still follow the migration checklist. The old database can stay read-only for history.
Budget for the rules, not for a clone
A like-for-like clone is a 4–12 month programme and sits at the top of the ₹2–15 lakh India range, or beyond it once every private screen is in scope. A first release of the real documents is often 2–4 months.
Bring the list of documents, not a screenshot of every menu, to a free audit.
Frequently Asked Questions
Can we run the old system in parallel?+
For a short check of balances, yes. Entering every new document in both systems doubles the work and splits the truth.
Who writes down the hidden rules?+
The person who uses the screen, with the implementer in the room. The original developer is useful and is not required if the rule is visible in a real document.
Do we have to move historical transactions?+
No. Move opening balances and open documents. Leave closed history where it is.