Choosing an ERP system is one of the most structural decisions for any business. A poor selection costs on average 2.5 times the initial budget in correction costs, redesigns, and lost productivity. This guide provides the field-tested methodology used by experienced CIOs.
This isn’t a theoretical guide. Every step comes from dozens of observed projects — both successful and failed ones. The goal: to help you reach the negotiation table with vendors in a position of strength, not as a naive buyer.
What you’ll find in this guide:
- 7-step methodology to structure your selection process
- Cloud vs on-premise choice demystified
- Ideal composition of the selection committee
- Industry-specific requirements not to overlook
- Decision matrix to objectively choose between finalists
Estimated reading time: 12 minutes. Share with your steering committee before first vendor contact.
Step 1: Define Functional Scope Before Looking at Vendors
The classic mistake: starting with vendor feature catalogs. Generic ERP systems cover 200 to 500 modules — no need to evaluate them all.
Start by mapping your critical processes:
- Which processes generate the most value?
- Which processes cost the most in human resources today?
- Which integrations with existing systems are non-negotiable?
Tool: the MoSCoW matrix (Must/Should/Could/Won’t) applied to business processes. List your requirements, categorize them, then weight them according to their business impact.
Step 2: Qualify the ERP Market According to Your Context
The ERP market segments into three main tiers:
Tier 1 — Enterprise (SAP S/4HANA, Oracle Cloud ERP): for companies with €500M+ revenue or international groups with complex processes. Budgets: €500K to several million euros.
Tier 2 — Mid-market and large SMEs (Microsoft Dynamics 365, Sage X3, Infor LN): the most active segment. Budgets: €150K to €500K.
Tier 3 — SME and startups (Odoo, NetSuite, Acumatica): faster deployments, fewer customizations. Budgets: €20K to €150K.
Not positioning yourself in the right segment is one of the main causes of failure. An SME choosing SAP for its reputation will suffer from unnecessary complexity. A mid-market company choosing Odoo for its budget will quickly hit the tool’s limits.
Step 3: Write a Structured RFP (Request for Proposal)
The RFP is your selection weapon. A good RFP:
- Describes your context: industry, size, transaction volumes, number of users per module
- Lists your functional requirements by domain (finance, purchasing, production, HR, etc.) with their MoSCoW priority
- Frames non-functional requirements: performance, availability, security, GDPR compliance
- Specifies integration constraints: CRM, e-commerce, WMS, BI
- Requests references: customers in your industry, of comparable size
Send the RFP to 4 to 6 vendors maximum. Beyond that, comparison becomes unmanageable. For more details, check our guide on how to write an ERP requirements document.
Step 4: Evaluate Demonstrations Objectively
Commercial demonstrations are designed to impress, not to evaluate. Here’s how to frame them:
Prepare test scenarios based on your real processes, not scenarios proposed by the vendor. For example: “Show me how you handle a supplier return with a multi-currency credit note when the original purchase order was modified.”
Form a mixed evaluation team: CIO, CFO, purchasing director, production key user. Each participant evaluates the demo according to their criteria grid.
Score systematically on a weighted grid rather than relying on impressions. A beautiful UI design isn’t worth much if financial processes don’t match.
Step 5: Analyze Total Cost of Ownership (TCO) Over 5 Years
The price displayed by sales teams only represents 30-40% of the real cost. TCO includes:
| Item | Typical TCO Share |
|---|---|
| Licenses / SaaS subscription | 25–35% |
| Integration and deployment | 30–40% |
| Customizations | 10–20% |
| Training | 5–10% |
| Maintenance and upgrades | 15–25% |
Always ask for:
- Cost of major upgrades
- Cost of additional modules you might need
- Annual maintenance rates (typically 15–22% of license price)
- Cost of migration if you want to change vendors in 7 years
For detailed cost analysis, check our article on the real cost of an ERP project.
Step 6: Verify References in Your Industry
Request 3 customer references in your industry and of comparable size. During reference calls, ask these key questions:
- Did you respect the initial timeline? If not, why?
- Did the final budget exceed the estimate? By how much?
- What was the adoption rate at 6 months, at 18 months?
- If you had to do it again, would you change vendors? Why?
- What’s your satisfaction level with support?
A vendor who hesitates to provide references or only offers handpicked showcase customers is a red flag.
Step 7: Negotiate the Contract with a Specialized Lawyer
The ERP contract is a complex document that commits your company for 7-10 years on average. Some vigilance points:
- Exit clause: what happens if you want to migrate to another vendor? Do you really own your data?
- Availability SLA: 99.5% availability represents 43 hours of downtime per year — acceptable?
- Price evolution: are annual price increases capped?
- Customizations and intellectual property: who owns specific developments?
Legal advice: Have the contract reviewed by a lawyer specialized in IT law, not by your usual business law counsel. Reversibility, liability, and data ownership clauses in SaaS contracts have subtleties requiring specific expertise. The cost of a consultation (€2,000 to €5,000) is negligible compared to contractual risks of a 7-year commitment.
Negotiation Points Often Left on the Table
Vendors frequently grant:
- One free quarter of subscription on a 3-year commitment
- Additional licenses at reduced rates for future growth
- Training included in deployment price
- Price freeze for 2-3 years
Integrators generally accept:
- Penalty clause for delays attributable to their team
- Team continuity commitment for the first 6 months
- Structured knowledge transfer to make your team autonomous
Cloud vs On-Premise: The Structural Choice of 2026
In 2026, the majority of new ERP implementations are done in SaaS (cloud) mode. But this choice deserves rigorous analysis according to your context.
Opt for SaaS if:
- You have teams distributed across multiple sites or working remotely
- You want automatic updates without internal technical management
- You don’t have an IT team capable of managing server infrastructure
- Your industry doesn’t impose restrictions on data location
Opt for on-premise if:
- Your data is subject to strict regulatory constraints (defense sector, sensitive medical data, classified data)
- Your IT team has the skills to manage infrastructure
- You have a deep customization need that would be blocked in SaaS
The hybrid option is increasingly common: SaaS ERP for transverse functions (finance, HR), with specialized on-premise modules for the most sensitive processes.
Remember: 80% of companies that chose on-premise for security reasons 5 years ago could have opted for SaaS with adequate certifications (ISO 27001, SOC 2, FedRAMP). Check certifications before excluding cloud.
For detailed comparison, check our article ERP cloud vs on-premise.
Involve the Right Stakeholders in the Decision
Choosing an ERP commits the entire company. The selection committee must be multidisciplinary:
The essential ones:
- The CIO or IT manager: evaluates technical aspects, security, integration
- The CFO: validates finance needs and TCO structure
- A business representative per key domain: purchasing, sales, production, logistics according to your activity
Often forgotten roles:
- HR manager if the ERP includes an HRIS module
- Quality/compliance manager for regulatory requirements (GDPR, industry standards)
- A field user per domain: their feedback on ergonomics and daily practicality is irreplaceable
Decision mechanism: define upfront who has the final word. A selection committee without arbitration rules ends in soft compromise — everyone chooses “their” preferred ERP and we end up with a list of 3 tied finalists without decision.
Industry-Specific Requirements Not to Neglect
All ERPs are not equal across all industries. Here are the most common vigilance points:
Manufacturing and fabrication: verify the depth of the MRP (Material Requirements Planning) module, multi-level BOM management, lot/serial number tracking, and capacity planning by work center.
Distribution and wholesale: evaluate multi-warehouse management, complex pricing rules (cascading discounts, customer-specific pricing, temporary promotions), and EDI integration with major customers.
Professional services: look for robust project management (time tracking, progress billing, profitability by deal), human resources, and recurring billing.
E-commerce and retail: omnichannel integration (online store, ERP, logistics) is critical. Check native connectors with platforms (Shopify, Magento, WooCommerce) or API quality.
Public sector and associations: requirements for budget management by envelope, analytical tracking, and production of profit & loss statements by activity are often poorly covered by standard SME market ERPs.
The Final Decision Matrix
To objectify your choice between 2 or 3 finalist vendors, build a weighted matrix:
| Criteria | Weight | Vendor A | Vendor B | Vendor C |
|---|---|---|---|---|
| Functional coverage | 25% | /10 | /10 | /10 |
| 5-year TCO | 20% | /10 | /10 | /10 |
| Proposed integrator quality | 20% | /10 | /10 | /10 |
| Adoption ease (UX) | 15% | /10 | /10 | /10 |
| Vendor stability | 10% | /10 | /10 | /10 |
| Industry-specific coverage | 10% | /10 | /10 | /10 |
Weightings should be adapted according to your context. The exercise forces each committee member to argue their scores — that’s often where real disagreements emerge and get resolved.
Summary: 5 Mistakes to Avoid
- Choosing based on reputation rather than functional fit
- Neglecting the integrator: a good ERP with a bad integrator = failed project
- Under-dimensioning change management (typical budget: 15% of total project)
- Wanting to customize everything rather than adapting processes to the ERP
- Neglecting post go-live governance: who decides on changes after production deployment?
ERP selection takes on average 6-12 months to be done properly. It’s a time investment that pays off greatly over the project duration.
