Odoo or custom software: the question is wrongly framed

Why the direct comparison misleads

The question almost always arrives in this form: "we are hesitating between Odoo and custom development". It assumes both cover the same ground and that one must be chosen. They do not, and that is why projects starting from this question often end badly.

An ERP is a standard product, designed to suit thousands of companies. Its value comes precisely from not being specific to you: Belgian accounting, VAT and bank reconciliation work the same at your place as at your neighbour's, and there is no point rebuilding them.

Custom software does the opposite. Its value comes from matching a way of working that exists only at your company, the one that explains why customers come to you rather than elsewhere.

Drawing the line

There is a simple test, and it requires no technical skill. Take your processes one by one and ask: does a competitor do exactly the same thing?

If the answer is yes, the process is standard. It belongs in the ERP, and having it built would be wasted money. Issuing an invoice, tracking stock, managing leave: nobody ever won a customer through their way of issuing invoices.

If the answer is no, you have something. A pricing logic of your own, a customer journey refined over years, a production method your competitors lack. Forcing it into a standard ERP amounts to erasing your advantage to save on tooling.

The hidden cost of each excess

Putting everything in the ERP looks thrifty, and sometimes is. The cost shows up later: teams keeping a spreadsheet alongside because the screen matches nothing, stacked configurations nobody understands any more, and an upgrade that becomes impossible.

Building everything custom looks powerful, and sometimes is. That cost also shows up later: you maintain an accounting system the law changes every year, when a publisher would do it for you at an unbeatable price.

Both excesses are expensive. The split costs the right price.

What a good split looks like

In the projects we run, the architecture that ages best divides the roles this way. The ERP holds administration: invoicing, accounting, purchasing, payroll. The business platform holds the core activity, with the team's vocabulary and screens. The two exchange through an API, in both directions.

A telling example: a coliving operator manages leases, condition reports and a tenant portal in a dedicated platform, because none of that exists in an ERP. Rents and charges then flow to Odoo, which issues the invoices and keeps the books. Nobody retypes anything, and each tool does what it does best.

When a single part is enough

Not every company needs both. A trading company whose business is buying and reselling will find the essentials in an ERP, with a few adjustments. A start-up whose product is the software often needs no ERP at all in its early years.

The rule is not to have two tools, it is to stop asking one tool for what it cannot do.

Our position

KERN-IT digitalises the core business. We do not replace an ERP that works, and we say so to clients who arrive thinking everything must be rebuilt. When Odoo or another ERP is already in place and doing its job, the right decision is to keep it and build alongside it what it will never cover.