Odoo vs SAP vs Dynamics: honest comparison for Spanish SMEs 2026

Why this comparison is different

Most ERP comparisons are written by companies that sell one of the products being compared. The result is predictable: their own product always wins in every category and competitors mysteriously have more «limitations». This is not that comparison.

I deployed Odoo as CEO at my own company (Cymit Química, exit to Grupo PALEX) and as a consultant on external projects. I evaluated SAP Business One and Microsoft Dynamics 365 in real selection processes. And I have seen organisations where Odoo was clearly the best choice, and others where it was not. I share what I have seen, with real numbers, so you can make an informed decision.

The goal of this article is not to convince you of anything. It is to give you the information you need to ask the right questions of your future ERP partner.

The three systems: what they really are

Odoo

Odoo is a Belgian-born open-source ERP, currently at version 17/18, with more than 12 million users worldwide. It comes in two editions: Community (free, open source) and Enterprise (paid licence, additional modules, official support). Its modular architecture lets you activate only the modules you need: sales, purchasing, accounting, manufacturing, e-commerce, CRM, HR, etc. The key differentiator is that everything is natively integrated: no third-party connector is needed to make accounting talk to inventory.

The OCA ecosystem (Odoo Community Association) adds hundreds of quality-vetted modules for specific needs. In Spain, the accounting and payroll localisation is well covered in both Enterprise and OCA modules.

SAP Business One / SAP S/4HANA

SAP has dominated the global ERP market for decades. For SMEs, the relevant product is SAP Business One (B1), designed for companies with up to 150 users. Mid-to-large enterprises enter the territory of SAP S/4HANA, which is a system in a completely different investment category. This article primarily compares SAP Business One with Odoo, because SAP S/4HANA does not compete in the same market segment as Odoo for SMEs.

SAP Business One has a solid reputation in distribution and manufacturing sectors, robust manufacturing modules and a broad partner network. It also has a steep learning curve, structured implementation methodologies and a licensing model that penalises user growth.

Microsoft Dynamics 365 Business Central

Microsoft Dynamics 365 Business Central (formerly Dynamics NAV / Navision) is Microsoft’s ERP for SMEs and mid-sized companies. Its native integration with the Microsoft ecosystem — Office 365, Teams, Power BI, Azure — is its strongest selling point for organisations already living in that ecosystem. It is a mature system, with an enormous partner network in Spain and good coverage of standard processes. Its licensing model is exclusively cloud (SaaS), meaning a recurring monthly cost per user with no on-premises installation option for new licences.

Total cost of ownership comparison (3-year TCO)

The price shown on these systems’ websites is always just one part of the real cost. The 3-year TCO includes licences, implementation, infrastructure, maintenance and support. The figures below are based on real projects in Spain for a reference company of 20–50 users with distribution or light manufacturing processes.

Note on these ranges: the ranges are wide because the real cost depends heavily on process complexity, required customisations and partner quality. A poorly planned Odoo project can cost more than a well-executed SAP Business One. The licence figure is the easiest data point to compare and the least relevant for making the right decision.

Implementation timeline

Odoo tends to go live faster because its module-based configuration model allows going live with a subset of functionality and activating the rest incrementally. SAP Business One and Dynamics 365 BC have more structured implementation methodologies (ASAP, Sure Step) that add rigour but also time. In practice, the factor that most delays any implementation is not the system: it is the client’s clarity about their own processes and the availability of their decision-makers.

Flexibility and customisation

This is the area where the difference is most pronounced.

Odoo: open source as a customisation lever

Odoo is open source. The source code is yours to read, modify and extend. This has a real impact: when a business process does not fit exactly within the standard, a developer can create a custom module that integrates natively with the rest of the system. No third-party APIs, no fragile connectors: it is the same framework.

The OCA module ecosystem contributes more than 2,000 additional open-source modules, many of them with proven production quality. For specific sectors — chemical distribution, equipment rental, technical project management — OCA modules exist that address real needs without custom development.

The trade-off: a poorly implemented customisation in Odoo is technically easier to build than a poorly implemented one in SAP, which means there are more Odoo projects with accumulated technical debt. Open source does not guarantee quality; it guarantees access.

SAP Business One: customisation through certified partners

SAP Business One is customised primarily through the SAP SDK (in C# or VB.NET) or through modules from certified ISV partners. It is a very comprehensive system in its standard coverage, but out-of-standard customisations are expensive, require SAP-certified developers and, above all, are difficult to maintain across versions. A customisation built for SAP B1 8.8 may need to be fully rebuilt for SAP B1 10.0.

Microsoft Dynamics 365 BC: AL extensions

Dynamics 365 Business Central uses the AL language for extensions and no longer allows direct code-base modifications (extension model). This is cleaner from a maintenance standpoint but limits what can be customised without going through Microsoft AppSource. The AppSource app ecosystem is broad but quality apps are scarce in very specific niches of the Spanish market.

Scalability

All three systems scale vertically without issue up to mid-sized companies of 200–500 users. Differences emerge in how they behave at greater scale and in the cost-growth model:

• Odoo: scales horizontally well with the right architecture (multiple workers, PostgreSQL replication, load balancing). Infrastructure costs scale more slowly than the Enterprise licence because the per-user pricing model has negotiable limits above a certain scale. I have implemented Odoo architectures with 99.9% SLA using Patroni + HAProxy in real production.
• SAP Business One: designed for companies up to ~150 users. Beyond that, SAP steers towards S/4HANA, which represents a significant qualitative and quantitative investment leap. Licence costs scale linearly with users.
• Dynamics 365 BC: scales well in Microsoft Azure’s SaaS model. The issue is that costs scale directly with users and there is no self-hosting option to control that cost.

Vendor lock-in vs codi obert

This is the argument most frequently underestimated in ERP decisions, and the one that costs the most in the long run.

Odoo Community: maximum technological sovereignty

With Odoo Community, the source code is yours. The database is standard PostgreSQL. You can change partner, hire a different consultant, migrate to a different server or fork the code if necessary. Nobody can revoke your access or raise the licence price because there is no licence. This is the definition of technological sovereignty.

Odoo Enterprise: moderate and manageable dependency

With Enterprise, the dependency is real but controlled: if you stop paying the licence, the Enterprise-exclusive modules (Studio, Sign, IoT, etc.) stop working, but your entire database and Community modules remain operational. You can migrate to Community if needed, though you would lose functionality. The risk is manageable.

SAP Business One: structural lock-in

SAP Business One has deep lock-in: the data format is proprietary, the business logic is encapsulated, and migrating away from SAP is a major project. In practice, many SMEs that have been on SAP B1 for 10 years stay because the perceived exit cost is higher than the cost of continuing. This is not necessarily bad if the system is working, but it is a real strategic risk.

Dynamics 365 BC: total cloud dependency

Dynamics 365 BC in its current SaaS model (the only option for new licences) means your data is in Azure, the price is set by Microsoft, and service availability depends on Microsoft. Updates are automatic and mandatory, which can create friction with specific customisations. There is no on-premises option for new deployments.

Support: who helps you when something goes wrong

An important nuance about support in Odoo: the quality of support you receive depends almost entirely on the partner you choose, not the vendor. Odoo S.A. provides access to security patches and the platform, but the resolution of functional incidents lies with the consultant or partner. Choose your partner carefully: it matters more than the system.

When to choose Odoo

• SME with 5 to 200 users that needs a complete ERP without a prohibitive licence cost.
• Company that values technological sovereignty and does not want to depend on a single software vendor.
• Businesses with unique processes that require real customisation: Odoo is the easiest system to extend with your own code.
• E-commerce integrated with the back office: the native Odoo online store + inventory + accounting integration has no direct equivalent in SAP B1 or Dynamics BC without connectors.
• Startups and scale-ups that want to grow fast without licence costs scaling prohibitively.
• Companies that already have or want to build an internal technical team: access to the source code gives them real autonomy.

When to choose SAP Business One

• Complex manufacturing company with advanced MRP, capacity planning or batch management needs that require SAP’s functional depth in those areas.
• Company that belongs to a corporate group already using SAP at corporate level and needs native integration with SAP S/4HANA or SAP BW.
• Regulated sectors (pharmaceutical, food) where SAP’s certified audit trail and traceability have differential value.
• Company with a trusted SAP partner with a proven track record in their sector and no desire to change.

When to choose Dynamics 365 Business Central

• Company fully integrated in the Microsoft ecosystem: Office 365, Teams, Power BI, Azure Active Directory. The native integration justifies the cost.
• Professional services or consulting firm that heavily uses Outlook, Teams and Excel and wants the ERP to be a natural extension of those tools.
• Organisation that prefers the SaaS model managed by Microsoft and does not want to deal with infrastructure, upgrades or server security.
• Company migrating from an older version of Dynamics NAV / Navision that wants continuity with the previous system.

The honest decision table

The question you should ask before deciding

After seeing dozens of ERP selection processes, the question most frequently skipped — and the most expensive to overlook — is this: what happens if in 5 years I want to switch?

With Odoo Community the answer is: you have the code, you have the database in standard PostgreSQL, you have documentation. Switching is costly but viable. With SAP Business One or Dynamics 365, historical data is trapped in proprietary formats or in the vendor’s cloud. Migration away requires complex extraction and transformation projects.

This does not mean Odoo is always the best option. It means that lock-in has a real cost that rarely appears in price comparisons.

In my experience: for the vast majority of Spanish SMEs with up to 150 users and distribution, commercial, logistics or service processes, Odoo fully covers the needs and has a significantly lower TCO. For very complex manufacturing or deep integration with SAP or Microsoft ecosystems, the competitors have real arguments.

The best decision is not the one with the lowest price in year 1. It is the one with the best cost-outcome-risk ratio in years 3 to 5.

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