Decide what your gap analysis must settle before go-live.

This guide helps you decide whether a gap analysis has to be finished before you go live on standard Odoo, or whether it can come afterwards. The short answer: do a short one before go-live, aimed at two things only, the decisions Odoo makes hard to reverse once transactions exist and anything the business cannot operate without. Custom features, extra reports and screen changes can wait until people have used the standard system. Odoo's own implementation methodology divides the work the same way.

It is written for owners and operations or finance leads offered a fast go-live by Odoo, a partner or their own team. Software behavior was checked in the source code of Odoo 19 and 20.

Before you start

• Your process list: the steps from quote to payment and from purchase to stock, with the exceptions people currently handle by hand.
• Version and edition: Odoo 19 or 20, Community or Enterprise. Some behavior below differs between versions.
• The go-live date, and the person who will confirm the business can run on the system.
• Terms used: a gap analysis compares each business process with how standard Odoo handles it and records a decision for every difference. Go-live is the day real transactions start in Odoo. A posted entry is an accounting record that has been confirmed and counts in the books. A lock date is a date up to which Odoo refuses changes to the books.

What a gap analysis actually produces

For each process, a gap analysis answers three questions: what the business does today, what standard Odoo does, and what to do about the difference. The usual answers are to adjust the process, configure Odoo, build something, or defer. The result is a list with a decision and an owner per line, split into day-one items and items that can follow.

Odoo's Implementation Methodology, a guide Odoo published for its own project leaders (dated January 2020), puts the gap analysis first and budgets about 10% of project time for it. On projects expected to take under four months, it is folded into the kick-off rather than run as a separate phase. The same guide sorts development into work the business cannot operate without, done before production, and work for a second deployment, which it suggests reviewing about a month after go-live. Going live on standard Odoo and analysing first are therefore compatible: the analysis decides how small day one can be.

What is cheap to change after go-live

• Fields and screens added with Studio (Enterprise). Odoo's upgrade service carries Studio changes to new versions while Studio stays installed and the subscription is active.
• Warehouse steps. Moving between one, two and three step receipts or deliveries is a warehouse setting, and Odoo rebuilds the routes. Transfers in progress may still follow the old steps, so finish them first.
• Lot and serial tracking. It can be switched on for a product later. If stock is on hand, Odoo warns that those units have no lot or serial number and points you to an inventory adjustment to assign them.
• Report layouts, approval steps and automations. These are configuration that can usually be changed at any time.

What is expensive to change after go-live

• Fiscal localization. The Package that loads your chart of accounts and taxes, in the Accounting settings, becomes read-only as soon as the company has any journal entry, even a draft.
• Company currency. Odoo refuses to change it once journal items exist.
• Tax-included prices. In Odoo 19 the Prices setting, which decides whether product prices include tax, locks once a journal entry is created. Odoo 20 allows a later change.
• Posted accounting entries. While an entry is posted, Odoo refuses changes to its lines, date, partner, currency or payment terms. Resetting it to draft is blocked if its date falls on or before a lock date without an exception, or if the entry has been secured. The Hard Lock Date, set in Enterprise under Accounting > Accounting > Closing > Lock Dates, allows no exceptions and can only move forward. A mistake in a locked period is then corrected with a new entry, such as a credit note or a reversal.
• Costing method with stock on hand. Each product category has a costing method: Standard Price, First In First Out or Average Cost. A change is allowed, but Odoo then recalculates the cost of every product in the category from its stock history, and Odoo 20 also revalues stock movements since the last inventory closing. Posted entries stay as they were, so your accountant has to handle the difference.
• Units of measure. The ratio of a unit, such as 12 Units to a Box, cannot be changed while open transfers or stock on hand use it. Changing a product's own unit is allowed, but Odoo warns that it converts one for one, so a past order for 10 Units would then read 10 Boxes.
• Company structure. Odoo refuses any change to which company is a branch of which, and a warehouse cannot be moved to another company. It has to be archived and recreated.

A decision rule for the pre-go-live list

The rule below is a recommendation, and its reason is simple: a gap found after go-live has to be fixed on live data, and for the items above Odoo either blocks the fix or makes it an accounting exercise. Put an item on the before-go-live list if any of these is true:

1. Odoo locks it, or makes it costly, once transactions exist.
2. It changes how quantities or values already recorded are read, as costing methods and units of measure do.
3. A tax filing or legal requirement depends on it.
4. Without it, the business cannot take an order, receive or ship goods, invoice, or get paid.

Everything else goes on the second list, with an owner and a review date about a month after go-live. With a fixed date and little time, rules 1 and 3 are the minimum, because those decisions are hardest to revisit.

Who can run the analysis

The analysis can be done in-house, by Odoo or by a partner. Doing it yourself costs time, and works best when whoever keeps the books reviews the accounting items. Odoo's Success Packs are prepaid consultant hours, and Odoo says its consultant analyzes how the business runs before implementation; on 7 October 2026 the smallest pack was 4 hours for CAD 850.00, or CAD 722.50 as a new customer's first pack. Odoo states that partners usually charge per day of consulting or development. Whoever proposes going live first, ask which of the items above they will settle before go-live and who owns the second list.

Check the plan in front of you

• Every process on your list has a decision: adjust, configure, build or defer.
• Fiscal localization, currency, tax-included prices on Odoo 19, company structure, costing methods and units of measure are set and tested in a practice database.
• Your accountant has reviewed the chart of accounts and taxes before the first invoice.
• A return, a partial delivery and a credit note have been run end to end in the practice database.
• The deferred list has an owner and a review date.

Steps verified on Odoo 19 and 20. Menus and labels can differ on other versions.

Common questions

What is a gap analysis in an Odoo implementation?

It compares each business process with how standard Odoo handles it and records a decision for every difference: adjust the process, configure Odoo, build something or defer it. The result also separates what is needed on day one from what can follow go-live.

Is it safe to go live on standard Odoo before a full gap analysis?

It can be, if a short analysis first settles the decisions Odoo makes hard to reverse and anything the business cannot run without. Odoo's own methodology folds the gap analysis into the kick-off on small projects and defers non-essential development to a second deployment.

Which Odoo settings cannot be changed after go-live?

The fiscal localization package and the company currency lock once journal entries exist, and in Odoo 19 so does the tax-included prices setting. Odoo also refuses changes to the company branch structure, and a Hard Lock Date can only move forward.

Can I edit a posted journal entry in Odoo?

Not while it is posted. It can be reset to draft unless its date is on or before a lock date or the entry has been secured, in which case the correction is made with a new entry such as a credit note or reversal.