In many SMEs, the need for an ERP arises when historical tools reach their limits: multiple Excel files, scattered data, lack of visibility on profitability, or manually constructed reports.
The problem is not always the lack of tools. It is often the absence of a structured management system that allows the manager to steer their business with reliable and centralized data.
It is precisely at this moment that an ERP like Odoo becomes a true tool for transformation and management.
At Advanced Conseil, we regularly take over Odoo projects after an initial integrator. Here are the 5 mistakes we most often find in SMEs that implement Odoo.
Mistake #1: Considering Odoo as just an IT project
This is probably the most common mistake.
Many companies approach Odoo as a software change intended to replace several existing tools. In reality, an ERP profoundly transforms the functioning of the company: commercial management, finance, production, purchasing, reporting, flow validation, or even margin tracking.
An ERP project is therefore not just a technical project.
It is primarily a project of structuring and management.
Projects that fail are not necessarily those that have the wrong tools. They are often those that have not sufficiently defined their management objectives and the indicators that are truly useful to the manager.
A high-performing ERP must provide a clear, centralized, and actionable view of the company's activity.
Before the ERP, many leaders manage their company with scattered data and several weeks behind the operational reality.
A successful implementation, on the contrary, allows for a much smoother view of cash flow, margins, business flows, and company performance.
The mistake that no one will tell you before signing with your integrator
Your Odoo integrator has a financial interest in the complexity of your project. The broader your scope, the more service days they have. This is not a criticism — it is the reality of the business model of IT service companies.
The problem: no one on the client side challenges this scope with a financial perspective. The internal CFO is often not involved in the configuration decisions. Management approves technical specifications that they do not understand. And the integrator builds what they are asked for — even when what they are asked for is unnecessary, overly complex, or contrary to Odoo best practices.
This is precisely the role that Advanced Conseil plays in Odoo projects: project management assistance (PMA) with dual expertise in finance and technology. We challenge the integrator, arbitrate the scope choices, and maintain a view of the return on investment at every project decision.
Error #1 — Trying to exactly replicate old Excel files in Odoo
Many SMEs seek to recreate their old Excel files and historical habits in Odoo. The result: they unnecessarily complicate the ERP and lose a large part of its value.
An ERP project should be an opportunity to simplify and standardize the company's processes, not to reproduce old dysfunctions in a new tool.
Why it is a mistake
Odoo 16/17/18/19 covers 80% of the needs of a standard SME without specific development. It is the remaining 20% that costs 80% of the customization budget — and creates 100% of the maintenance problems with each version upgrade.
Each specific development in Odoo is a technical debt. When Odoo releases a new version, your specific developments must be re-tested, sometimes re-written. This recurring cost is rarely anticipated in the initial budget.
What to do instead
Take advantage of the project to simplify and standardize processes, relying on Odoo's native functionality. The question to ask for each specific development request: "Can we change our process to avoid this development?" In 70% of cases, the answer is yes — and that is the right answer.
Error No. 3 — Wanting to deploy all modules before structuring the management
Many SMEs seek to immediately activate all available modules: CRM, sales, purchases, production, inventory, HR, or accounting.
However, an effective ERP project primarily relies on the flows that are truly critical for the manager: commercial visibility, cash flow, margins, billing, or operational monitoring.
The real challenge is not to have "all Odoo". The goal is to gradually build a coherent, usable, and useful system to manage the company.
Laurent Blanchet: "An Odoo project should not be approached as just a software change. The real challenge is to enable the leader to regain a clear vision of their business: cash flow, profitability, margins, and operational performance. Successful projects are those that prioritize management before considering technical aspects."
The choices made at the start of the project will have a direct impact on the quality of future management: margin tracking, cash flow visibility, reporting, or profitability.
A small business does not always lack strategy. It often lacks tools to transform that strategy into concrete decisions, and therefore, one must think about management at the beginning of the project.
What the small business does
It addresses the billing rules at the end of a project—subscriptions, automatic renewals, deposits, credits, discounts, specific VAT rules. These rules are discussed once everything else is already set up.
Why it is a mistake
Invoicing is the heart of the business cycle in Odoo. It conditions accounting, customer follow-up, reminders, and e-reporting. If its rules are poorly defined from the start, a significant part of the configuration will have to be redone.
The most common specific cases that create blockages: progress billing, recurring subscriptions with multiple pricing, deposits on orders, multi-site invoices, and intra-community VAT rules. Each of these cases must be tested in acceptance before going live — not discovered afterward.
What to do instead
Map out all your invoicing rules before the project starts, and check precisely what Odoo covers natively. Advanced Conseil conducts this invoicing audit during the scoping phase — before starting to configure anything.
Error #3 — Wanting to deploy everything & handle accounting later
Some small businesses seek to immediately deploy all available modules: CRM, sales, purchases, inventory, production, HR.... and postpone financial topics, finding that these subjects are complex to handle at the beginning.
In many ERP projects, financial topics come too late: reporting, cash flow, profitability, or KPIs are addressed after operational deployment.
However, the choices made at the start of the project will have a direct impact on the quality of future management.
This approach often creates unnecessary complexity and significantly slows down the project.
A successful implementation generally relies on a gradual and prioritized approach. The goal is first to structure the most critical flows for the management of the company: billing, cash flow, reporting, commercial management, or operational monitoring.
The real challenge is not to have "everything Odoo". The goal is to build a coherent, reliable, and truly useful system for the manager and the teams.
What the small business does
It starts by deploying sales, CRM, or operations, planning to "connect accounting later". Accounting is seen as a module to be added once the rest is functioning.
Why it is a mistake
The choices made at the launch of the project will have a direct impact on the quality of future management: margin tracking, dashboards, cash flow, or profitability. If accounting is added after the commercial modules, inconsistencies are discovered that require revisiting part of the already validated configuration.
What to do instead
Always start with accounting flows. This is the recommendation from Advanced Conseil in all Odoo projects we support. First, configure the chart of accounts, journals, VAT, analytical rules — then connect the commercial modules to it. In this order, inconsistencies are detected early and are inexpensive to correct.
Error #4 — Lack of financial oversight on the client side
What the small business does
It allows the integrator to manage the project alone, or entrusts the decisions solely to the operational teams. The internal CFO or the accountant is not involved in the configuration decisions.
Why it is a mistake
The decisions of an ERP project have direct financial consequences: which journals to create, how to structure the analytical axes, how to set up customer reminders, how to manage closures. These decisions cannot be made solely by technical or commercial profiles — they require a financial and accounting perspective.
What to do instead
Designate a financial referent on the client side — internal CFO, accountant, or outsourced CFO — who participates in all configuration decisions with arbitration authority. This role is played by Advanced Conseil in projects where we are project management assistance: we challenge the integrator on each choice, with a dual finance and Odoo perspective.
Error No. 5 — Neglecting team support and data quality before migration
A high-performing ERP should not complicate the daily lives of teams. On the contrary, it should streamline exchanges, centralize information, and simplify processes.
When employees understand the meaning of the project and have tools that are truly useful on a daily basis, adoption becomes much more natural and effective.
In many SMEs, users discover the new tool too late or perceive Odoo as an additional constraint. Result: poor adoption, process circumvention, and gradual return to old tools.
When employees understand the meaning of the project and the link to the company's objectives, adoption becomes much more natural and effective.
Error No. 7 — Neglecting data quality before migration
What the small business does
It directly migrates its existing data — customer records, suppliers, items, accounting history, inventory — without prior audit. Incomplete, duplicated, or inconsistent data is transferred as is into Odoo.
Why it is a mistake
A false stock migrated into Odoo remains false in Odoo — but now it generates errors in valuations, automatic replenishments, and accounting statements. A duplicated customer record creates duplicate reminders, errors in outstanding balances, and inconsistencies in business statistics. These errors propagate across all connected modules.
What to do instead
Devote 2 to 4 weeks to auditing and cleaning data before migration. It is a time investment that saves three times more after going live. Advanced Conseil conducts this data audit during the scoping phase, with a precise mapping of anomalies to correct before import.
Client case: Service SME with 40 employees — migration from Sage
We supported a service SME with 40 employees that used Sage along with several complementary tools. The main problem was not Sage — it was the proliferation of tools and the manual reprocessing that resulted. The manager lacked consolidated visibility over their activity.
Main difficulties identified during scoping:
- Duplicated customer records in Sage — about 30% of the records had a duplicate.
- Complex billing rules — recurring subscriptions with multiple pricing based on customer profile.
- No analytical accounting in place — the margin by activity was not known.
Our approach: accounting scoping first, cleaning customer data before migration, gradual deployment of modules (accounting then sales then CRM). Go-live in two phases to secure the teams.
Result: consolidated visibility obtained from the first months, double entries eliminated, first margin by activity available in real time. The manager was able, for the first time, to identify that one of his three activities was structurally loss-making — and make the decision to close it.
ERP and outsourced CFO: a complementary approach
An ERP like Odoo centralizes data. This data can thus be analyzed and then allow for optimizing management and profitability. The outsourced CFO helps the manager transform this data into decisions. He helps the manager interpret this information to make better decisions.
At Advanced Conseil, we believe that an ERP not only structures the tools. It also structures the way the manager pilots his company.
Our approach combines financial vision, process structuring, and strategic management.
The ultimate goal is not just to deploy software like Odoo. The challenge is to have a deployment tailored to needs that will allow the manager to regain visibility and manage his company with reliable, centralized, and real-time usable data.
At Advanced Conseil, we support SMEs with a dual vision: financial and operational. The goal is not simply to deploy Odoo, but to build a true management tool that allows the manager to make faster and better-documented decisions, in this we intervene to better optimize the role of the Odoo Integrator.
Odoo: a management tool before being software
Many SMEs still consider an ERP as a simple administrative tool. In reality, an ERP like Odoo mainly transforms the way the manager runs their business.
An SME does not always lack strategy. It often lacks tools to turn that strategy into concrete decisions.
At Advanced Conseil, we use finance and digitalization as levers for management. Our approach combines:
- process structuring,
- financial management,
- automation,
- and real-time visibility.
The goal is not just to deploy an ERP. The challenge is mainly to enable the manager to make better decisions based on reliable, centralized, and actionable data on a daily basis. To achieve this, we work in coordination with the integrator and users to ensure a successful implementation.
Frequently asked questions: Odoo implementation in SMEs
How long does it take to implement the Odoo Accounting module in an SME?
For SMEs with well-defined needs and clean data, between 3 and 8 weeks for the Accounting module alone. The number one condition to meet this deadline: the client's ability to make quick decisions and simplify certain processes rather than replicating them exactly in Odoo.
Should we start with accounting or sales in an Odoo project?
Always start with accounting. It structures the journals, VAT, analytical rules, and reporting — if it is added after the commercial modules, we risk costly reconfiguration. This is the systematic recommendation of Advanced Conseil in all Odoo projects.
Which Odoo version to choose in 2026 for an SME?
Odoo 17 or 18 according to your project schedule. Odoo 17 is the current LTS (Long Term Support) version — stable, well-documented, with a mature ecosystem of third-party modules. Odoo 18 brings significant improvements in accounting and electronic invoicing. Odoo 19 is available but young — we recommend waiting 6 to 12 months before adopting it in production.
Can Advanced Conseil take over an Odoo project that has started poorly?
Yes. We regularly take over Odoo projects after an initial integrator. Our approach: audit of the existing configuration within 48 hours, identification of correction priorities, re-establishment of structured financial management. Free diagnosis.
Advanced Conseil is a certified Odoo partner accountant. We work on implementation, configuration, project management assistance, and the takeover of Odoo projects in SMEs — with a dual expertise in finance and technical skills that integrators alone cannot provide. Based in Levallois-Perret (Hauts-de-Seine), just steps from the Anatole France metro.
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