What each option is
Odoo is a suite of business applications that share one database: accounting, inventory, sales, purchasing, manufacturing, HR and many more. The Community edition is open source and free. The Enterprise edition is a subscription priced per user that adds applications, support and version upgrades. Odoo's price list puts its no-code customization tool, Studio, and hosting outside Odoo's own cloud on its Custom plan. An implementation configures the suite for you, migrates your data and trains your people, usually through a partner.
A custom ERP is a system designed around the way your company works. The data model, the screens and the rules follow your processes. It does only what you asked for, which is its strength and its cost.
The two options at a glance
| Odoo implementation | Custom ERP | |
|---|---|---|
| Starting point | Working applications on the first day | A blank page and your process maps |
| Breadth | Wide. Most departments are covered by an existing app | Narrow at first. Each area is built when it is needed |
| Fit to your process | Good where you are standard. You adapt, or you customize | Exact, for the processes you choose to build |
| Customization | Configuration first, then Studio on the Custom plan, then modules written by developers | Everything is built for you, so there is no boundary |
| Upgrades | A new major version each year. Enterprise upgrades cover standard apps and Studio customizations, and custom modules must be ported before you can move | No forced versions. You decide when anything changes |
| Cost shape | Per-user subscription on Enterprise, plus implementation and customization | A larger first investment, then hosting and maintenance, with no per-user fee |
| Ownership and licensing | Your data and your custom modules. Odoo itself is licensed by its vendor | Defined in the project agreement |
| Dependence | On the vendor's roadmap and on a partner who knows your setup | On whoever maintains the code, which is why documentation matters |
Edition contents, pricing and support periods are set by Odoo and change. The points above were checked against Odoo's documentation when this comparison was reviewed. Confirm them for the version you would install.
When each one fits
Implement Odoo when
- Your sales, purchasing, stock and accounting follow common patterns
- Several departments need a system at once
- You want one vendor's roadmap to carry tax and legal updates
- You accept changing some habits to match the product
- The number of users makes the subscription reasonable
Build custom when
- The process that earns your margin has no equivalent in a standard app
- A fit study shows most of the quote would be customization
- Hundreds of occasional users would each need a paid seat
- You must control when and whether the system changes
- The system is part of what you sell to your own customers
The customization trap
The worst outcome is a package modified until it behaves like custom software. You carry the subscription and the vendor's constraints, and you also carry a body of custom code that must be reworked for each new version. Four signs tell you a project is heading there.
- Customization is the larger part of the quote. Configuration and training should dominate an implementation.
- Core accounting or stock logic is being rewritten. Extending the edges is normal. Changing the center is a warning.
- Staff ask for the old screens back. The project is recreating the previous system inside the new one.
- The first upgrade keeps being postponed. Custom modules have to exist for the target version before a database can move, so each delay makes the next step larger.
Mixing the two
Most companies are standard in more places than they think and unusual in one or two. That suggests a mix. Finance, purchasing and inventory run on a standard system, kept close to its defaults so upgrades stay simple. The unusual process, such as quoting engineered products, scheduling crews or pricing by formula, runs in software written for it.
The two exchange data through the standard system's interface, so each figure is entered once. Our comparison of custom integrations and existing connectors covers how to join them.
A worked example
A wholesaler and a precast concrete maker
Both companies are invented. Each has about 60 staff and has outgrown spreadsheets.
- The wholesalerBuys, stores and sells packaged goods. Its processes are purchasing, stock, sales orders, invoicing and accounts.
- Its decisionAn Odoo implementation kept near standard, with two small extensions. Every process had a ready application.
- The concrete makerEach order is engineered. Quotes depend on moulds, reinforcement, curing time and crane capacity, and production is planned around the yard.
- Its decisionA custom system for quoting and production planning, connected to a standard package for accounting and purchasing.
The wholesaler's work looked like the product. The concrete maker's margin lived in a process the product had never seen.
A checklist to decide
Tick what is true. Ticks in the first four favor an implementation. Ticks in the last four favor custom work, at least for part of the system.
Odoo or custom
0 of 8 checkedWhat to do next
Ask for a fit study before any quote. It lists your processes and marks each as standard, configurable or custom. A study with few custom marks points to an implementation. One with many points to our custom ERP development page.
If you have a quote that feels heavy on custom modules, share it with us. We will tell you which parts we would keep standard and which we would build apart.
Common questions
Is Odoo free?
The Community edition is open source and free to use. The Enterprise edition, which adds applications, support and version upgrades, is a subscription priced per user, and Odoo's price list puts the Studio customization tool on its Custom plan. In both cases the larger cost is usually the implementation itself: configuration, data migration, training and any custom modules. Budget for the whole project, not for the license line alone.
What happens to custom Odoo modules when a new version arrives?
They have to be made compatible with the new version before the database can be upgraded. The Enterprise subscription covers upgrading standard applications, while modules written by you or by a partner are your responsibility unless a maintenance contract covers them. The more custom code a system carries, the more each upgrade costs, which is why staying close to standard matters.
Can we start with Odoo and move to custom software later?
Yes, and for part of the system it is often sensible. Run the standard areas in Odoo, learn where the product does not fit, then build custom software for that process and connect the two. What is hard is replacing a heavily customized installation in one step, so keep customization light while you learn.
How do we know whether our process is standard?
Describe it to someone who implements business systems for your industry and ask how the product handles each step. If the answers are settings and existing screens, you are standard. If they are workarounds, custom modules or a request to change how you work in an area that makes you money, that process is a candidate for custom software.