It’s no secret that an ERP system can come with a hefty price tag. Therefore, some businesses try to get their IT teams to develop one from scratch.
But while building your own ERP seems attractive in terms of cost, it’s also a sure-fire way to compile a lot of technical debt.
The full customisation control you were hoping for dissolves in endless code fixes and constant maintenance mode. Your business grows, but the ERP can’t keep up. And when your system breaks, there’s only you to fix it.
We break down the risks of custom ERPs and why open-source ERPs like Odoo offer a third path for both flexibility and safety.
Common myths and risks of custom-developed ERPs
When we ask potential clients why they want a custom ERP, they usually come up with a few reasons:
“We think it’ll be easier to do it ourselves”
“It’s cheaper if we do it in-house”
Still, more often than not, these reasons are rooted in misinformation.
Teams that venture into ERP development aren’t always equipped to engineer a whole system from scratch.
Their company often isn’t prepared to write every single line of code for accounting, inventory, sales processes, and everything in between - mentally or resource-wise.
Usually, they just don’t know what creating and implementing an ERP really entails.
Here are the most common myths in favour of a custom ERP development, debunked:
Cost efficiency
Myth
Custom-developing an ERP in-house is cheaper.
Truth
Initial implementation might be less costly, but technical debt in the long run won’t be sustainable.
You aren't just paying for the initial implementation, but also:
- Lifelong maintenance and the resources it takes to do it
- Security patching and regulatory compliance audits
- Infrastructure updates and internal support.
A commercial product handles it all for you. Most businesses find that the initial savings are quickly swallowed by the hidden costs of managing a full-scale software project internally.
Implementation & maintainability
Myth
It’s easier to do it ourselves; our IT team knows the business better than any consultant.
Truth
Your IT team is the expert on your infrastructure, not necessarily for accounting standards, tax compliance, or supply chain logic.
Implementing an ERP requires deep process knowledge in Finance and HR that developers often lack, leading to functional gaps.
Keeping your ERP compliant without this know-how is difficult and also dangerous.
Scalability
Myth
We only need a few features right now, so a custom build is faster to launch.
Truth
Businesses evolve. A custom system built for today’s needs becomes a blocker for next year’s growth.
For example, if you decide to open a new warehouse or sell in a different currency, you have to code those features from scratch, instead of just adjusting a setting.
Now, let’s say that you still want to develop an ERP system from scratch. This is a choice that can come with risks and long-term consequences:
- Maintenance burden: Every time a browser updates, an operating system changes, or a security vulnerability is discovered, your internal team must manually fix it. With each little fix, you need a maintenance window. You’ll need to steer team efforts from your main operations to maintain an ERP 24/7
- Knowledge black boxes: The system is only understood by the people who built it. If specific developers leave the company or team structures change, you risk being left with code that no one knows how to fix or update.
- Documentation gaps: Internal teams rarely document their code to the standard of a commercial product, making future changes slow and prone to breaking the system
- Legal non-compliance risk: While commercial ERPs update regularly to follow new tax laws (like VAT changes or E-invoicing mandates), a custom system is static. If the government changes a reporting law, your custom system is suddenly illegal until you internally rewrite the logic
- Disconnected business areas: There is no standardisation in processes between teams, and your business operations can easily become disconnected. With no proper integration, finance and sales might not be able to communicate properly
- No support or upgrades: You cannot update a custom ERP to a new version to get new features, and every new capability must be researched and coded from scratch. Not having a commercial system also means that if it breaks, there’s no one to fix it - it risks the entire well-functioning of your company.
Build vs buy - Odoo offers open-source flexibility without danger
Odoo works as the middle ground. It offers a hybrid model that provides the freedom of custom software without the risks of self-development.
Its modular structure and licences mean that it’s far more affordable than its competitors.
On top of that, Odoo is an open-source ERP - meaning that the source code is visible and accessible.
This allows for full customisation capacity within a single source of truth. Businesses are not dependent on a single company to access their own logic, which prevents vendor lock-in.
Feature | Custom-developed ERP | Odoo |
Maintenance | 20-25% of build cost annually (based on industry averages) | Included in predictable licensing |
Compliance | Manual coding for every small tax or GDPR change | Automated updates for global legislation |
Security | Reactive: You patch after a breach occurs | Proactive: Enterprise-grade daily patches |
Connectivity | Custom APIs are required for every 3rd party tool | Standard API connector and 40,000+ pre-built apps. |
Staffing risk | High: System can be orphaned if developers leave or teams change | Low: Access to a global partner network and vast community resources |
Odoo eliminates the trade-off between short-term low implementation cost and long-term high technical debt.
It provides the flexibility of a custom build with the safety and support of a global software product.
Let’s discuss how to tailor Odoo to your needs
Our experts can help you balance freedom and security to tailor Odoo for your business needs.