Many businesses approach ERP implementation with the expectation that the system will bend completely to their way of working. While that is understandable, it can quickly lead to an unsustainable level of customisation, creating long-term complexity, upgrade pain and spiralling support costs.
How much should we customise?
Odoo is powerful and flexible, but customising without discipline can lead to high costs, difficult upgrades and long-term technical debt.
Here is a guide to help you manage your Odoo customisation journey:
1) Start with the MoSCoW method:
Every business has unique needs, but that doesn’t mean every need requires a custom-built solution. Use the MoSCoW method to help you decide:
- Must-have – critical for business operations.
- Should-have – important, but manageable with a workaround.
- Could-have – nice to have, but not essential.
- Won’t-have – adds complexity without ROI.
This framework helps businesses avoid the trap of “we have always done it this way”. It is a mindset that can result in unnecessary spend and long-term technical debt.
2) Prefer configuration over code
Often, what you need is already possible in Odoo and it just needs to be set up properly. Configuration is easier to maintain, upgrade and support.
However, this also means being open to adapting your processes.
You might be thinking – shouldn't the system adapt to our processes instead? That is a natural question, but consider this: many of your current workflows were designed around the limitations of your old system or manual processes.
Rather than viewing this as a compromise, see it as an opportunity. Odoo's processes are built on best practices from thousands of successful implementations across diverse industries. By aligning with these proven workflows, you are not just getting software, you are inheriting years of collective business wisdom that can make your operations more efficient, reduce errors and position you for scalable growth.
The businesses that achieve the greatest ROI from their ERP investment are those that embrace this collaborative approach between system capabilities and process optimisation.
3) Plan for upgrades from day one
Custom code should never live inside core Odoo modules. Isolate it, document it and make sure the Odoo partner you are working with can support it long-term.
Odoo releases new versions regularly, typically every 12-18 months, bringing security updates, performance improvements and new features. If your customisations are tangled within core modules, each upgrade becomes a complex, expensive project that many businesses simply avoid, leaving them stuck on outdated, potentially vulnerable versions.
The cost of ignoring this advice is significant and businesses often find themselves paying 2-3 times the original customisation cost just to make poorly-built modifications compatible with newer Odoo versions. Or worse, having to completely rebuild functionality from scratch.
4) Ask the right questions
Before customising, challenge your team and your Odoo partner:
- Will this impact performance or scalability?
- Ask your partner to explain how the customisation will perform under load and whether it follows Odoo's performance best practices. Request load testing for any significant modifications.
- Can we achieve it with existing features?
- A good partner should exhaust existing options first and be able to explain why a custom approach is truly necessary.
- Is it documented and tested?
- Undocumented customisations become technical debt that haunts your business. Insist on comprehensive documentation that includes business requirements, technical specifications, testing procedures and user instructions.
- Will it make upgrades harder or more expensive?
- Your partner should provide a clear estimate of how this modification will impact upgrade costs and timelines. If they can't answer this question confidently, it is a red flag about their technical approach.
These questions might seem obvious but they are often skipped in the rush to solve immediate problems. Taking time to ask them upfront can save you significant costs and headaches down the road.
Customisations are investments, not expenses. Ensure each one delivers measurable value and won't become tomorrow's maintenance burden.