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In many companies of a few dozen people, the same order exists four times: in the sales rep’s CRM, in the workshop spreadsheet, in the invoicing software and in the head of whoever manages stock. Each copy is slightly wrong, and every month someone spends a day reconciling them. That is exactly the problem an ERP solves.
This guide is the entry point of the ERP cluster. It gives the overall map and points to the articles that detail each step, for teams of 20 to 500 people considering Odoo or Dolibarr.
In short
An ERP is worth it when the same data is re-keyed into several tools, not because the company has “reached a size”.
Dolibarr covers a simple, stable need well; Odoo covers a broad scope, with more modules and more configuration.
The written scope drives the project: a short, precise requirements document beats a list of modules.
Data migration and team adoption sink more projects than the choice of software.
You can keep existing tools and connect them to the ERP rather than replacing everything.
What an ERP really changes
An ERP (Enterprise Resource Planning) is not one more piece of software. It is a shared database where a quote becomes an order, then a delivery, then an invoice, without being retyped. Stock drops when the delivery leaves, margin is calculated on the real purchase price, and leadership reads figures nobody has touched up.
The difference with a CRM fits in one sentence: the CRM follows the relationship before the sale, the ERP manages what happens after. We detail the line in ERP or CRM: the real difference.
When to make the move
The signs are concrete: spreadsheet exports sent between departments every week, invoicing errors caused by re-keying, stock counted by hand before promising a lead time, a month-end close that takes several days. Three of these signs together justify opening the subject. The full list, with what to measure before deciding, is in When to move to an ERP.
Odoo or Dolibarr
Both are open source, both cover sales, purchasing, stock and invoicing. They do not target the same complexity.
Dolibarr
Quick to learn, essential modules
Simple hosting, on a small server
Suited to a stable scope of 5 to 50 users
Odoo
Very broad catalogue: manufacturing, projects, HR, point of sale
Deeper configuration, longer project
Free Community edition, Enterprise on subscription
Choosing between Odoo’s two editions has its own article, Odoo Community or Enterprise, and Dolibarr has its own, Dolibarr: who is it for. If a pure CRM is enough, our grid Twenty, Dolibarr or Odoo helps decide, and the cost of Odoo over three years lists the items to budget.
The steps of a project that holds
- Map the flows
Who enters what, where, and who checks it.
- Write the scope
The processes to cover, those that stay out, the business rules that are not negotiable.
- Choose the tool and the hosting
On that scope, not on a demo.
- Migrate the data
Clean before importing, test on a copy.
- Train by role
And open department by department.
- Measure
At 30 and 90 days what has actually changed.
Each step has its article: the requirements document, data migration, team training and the project’s return.
What makes an ERP project fail
Projects that go off the rails usually share the same causes: a scope that grows along the way, data imported as is, heavy customisation that blocks upgrades, and teams that keep their spreadsheet on the side. We detail them in Why ERP projects fail, with what prevents them.
Customisation deserves its own attention: every bespoke development is paid again at every new version. Customising an ERP safely gives the rule we apply.
Keeping what already works
An ERP does not mean throwing everything away. Accounting software the accountant likes, a sector-specific tool or an online shop can stay, connected to the ERP by connectors or an orchestrator such as n8n. That is often what makes the project acceptable to teams. See Connecting your business tools.
The topics that come next
Once the ERP is in place, other questions arise: e-invoicing, mandatory in France from September 2026, stock management, purchasing, manufacturing, projects in a services company, multi-company setups, access rights, dashboards and what AI brings to an ERP.
To choose a provider, Choosing an ERP integrator lists the questions to ask, and ERP in the cloud or on your own server helps choose the hosting.
The official sites of both projects remain the reference for current features: Odoo and Dolibarr.
Frequently asked questions
From how many employees do you need an ERP?
There is no threshold. The right indicator is the number of re-keyings between tools and the time spent reconciling figures. A team of 15 with stock and manufacturing may need one before a services company of 80 people does, because its flows depend on each other far more.
How long does an ERP project take?
For a sales, purchasing, stock and invoicing scope, count a few weeks for Dolibarr and several months for Odoo with manufacturing or several companies. Data migration and training often take as long as configuration, and they are the parts not to cut if you want to hold the date.
Can you start small?
Yes, and it is often the best choice: a first scope (sales and invoicing, for example), then purchasing and stock once the first batch is adopted. Both tools lend themselves to this, since modules are added without redoing everything, and the team learns on a scope it masters before widening.
What does Brain Plus AI offer?
Our CRM and ERP offer starts with a short scoping of the choice, then deploys Dolibarr or Odoo at a fixed price depending on the scope, with data migration, team training and a follow-up at 30 then 90 days to measure what has changed.
Sources
- Official Odoo website (new tab)odoo.com
- Official Dolibarr website (new tab)dolibarr.org
Jim · founder of Brain Plus AI
Also in erp: odoo and dolibarr
Practical guide4 min
ERP requirements document: the short template that works
An eighty-page ERP requirements document protects you from nothing, whereas a short document focused on flows and business rules makes a better project. The outline, section by section.
Understand4 min
When to move to an ERP: seven signs that do not lie
Company size does not tell you when you need an ERP, re-keying, stock gaps and slow closes do. Seven signs to check, and what to measure before deciding.
Understand4 min
Why ERP projects fail, and how to avoid it
ERP projects that go off the rails almost never stumble on the software, but on scope, data, customisation and adoption. Six causes, and the counter to each.