Decision guide · Updated quarterly
ERP replacement in 2027: upgrade, switch suites or build your own
Most companies replacing an ERP compare one packaged suite with another. In 2027 there is a third route, which is to own the system. This guide sets out the evidence on each, what it costs and how to run the project in stages.
Contents
- Why an ERP replacement is hard to get right
- The question behind the project has changed
- Four routes, compared
- How we compared the options
- The options, ranked
- The options compared
- The criteria
- What an owned AI operating system replaces
- What a replacement costs
- Legacy ERP modernization: whether the old system gets AI
- The replacement path
- What the end state looks like
- Sources
In brief
An ERP replacement has four routes in 2027: upgrade within the same vendor, switch to another packaged suite, build an AI operating system the company owns, or keep the old ERP on third-party support while deciding. Gartner puts the share of ERP initiatives that fail to fully meet their business case at 70%, so the route matters more than the brand. For an established company that wants to come out of the project owning an AI-native system instead of renting another rigid one, OpenLazarus is our top pick. Dynamics 365 is the closest packaged replacement with published prices, Odoo the lowest-priced suite, Rimini Street the way to buy time, and S/4HANA the route for groups committed to SAP.
- Own the system: OpenLazarus. Prebuilt ERP, CRM, mail and telephony modules on one AI and data layer, with the code owned by the company.
- Switch to another enterprise suite: Microsoft Dynamics 365 Finance and Supply Chain Management. Documented production and costing depth at a published $210 per user a month per application.
- Switch at the lowest published price: Odoo. Every app in one subscription from €19.90 per user a month in the first year, with an on-premise option.
- Keep the ERP and buy time: Rimini Street. Third-party support that the vendor says cuts annual support fees by up to 50%.
- Upgrade within SAP: SAP S/4HANA. A maintenance commitment to the end of 2040 for groups that stay with the vendor.
Why an ERP replacement is hard to get right
An ERP holds the ledger, the orders, the stock and the purchasing of a company, and everything else is wired to it. Replacing it is the largest software decision most management teams make, and the record is poor. Gartner’s senior director of ERP strategy puts the share of ERP initiatives that fail to fully meet their original business case at 70%, and the share that fail catastrophically at 25%1. ISG’s survey of 200 senior decision-makers at large companies found nearly 60% of SAP migration projects delayed and over budget2.
The failures are expensive and public. Lidl stopped its SAP-based merchandise system in July 2018 after about seven years; industry observers put the cost at around €500 million, a figure neither company confirmed34. Birmingham City Council’s Oracle programme rose from about £19 million to £170 million1.
Many companies are not choosing the moment. SAP ends mainstream maintenance for the core applications of Business Suite 7, which include SAP ERP 6.0, at the end of 2027, with optional extended maintenance to the end of 2030 at a premium of two percentage points on the maintenance basis56. In the German-speaking user group’s 2026 survey, 54% of member companies still ran ECC or an older Business Suite7. And the case for simply following the vendor is hard to make: in a Freeform Dynamics poll of 455 respondents, 95% of legacy users said building a positive case to migrate takes a big effort or is a real challenge8.
The question behind the project has changed
For three decades an ERP replacement meant choosing between packaged suites. The buyer accepted the vendor’s data structures, adapted its processes to the product or paid to customise it, and then paid a yearly fee to keep it running. That bargain made sense when software was expensive to write.
Two things have weakened it. The first is that companies are already doing their AI work somewhere other than the ERP. In the DSAG Investment Report 2026, 43% of member companies had implemented AI use cases; of those in production, 77% ran on non-SAP solutions and 3% on SAP’s7. The system of record has become the system the AI has to work around.
The second is that building software to fit one company has become far cheaper. Klarna’s chief executive described consolidating the data held in its many SaaS systems, Salesforce among them, onto an internal stack with AI tooling, while doubting that every company would do the same9. The caveat is fair. The point for an ERP buyer is narrower: a third route now exists beside "upgrade" and "switch", which is to own the system.
Four routes, compared
| Route | What it means | What the company ends up with |
|---|---|---|
| Upgrade | Move to the current product of the same vendor, for example ECC to S/4HANA | A newer rented or licensed suite, maintained by SAP to the end of 20406 |
| Switch | Replace the ERP with another vendor’s packaged suite | A different rented suite at a published price per user1011 |
| Build | Assemble an AI operating system from prebuilt modules, shaped to the company | A system whose code and data the company owns12 |
| Defer | Keep the ERP and move its support to a third party | The same system, a lower support bill by the vendor’s account, and more time13 |
The first two routes change the vendor’s name on the invoice and leave the arrangement intact. The third changes the arrangement. The fourth changes neither, and is useful as a way to fund and pace one of the others.
How we compared the options
We took one option for each route, and two for the switch route because the market offers an enterprise suite and a low-cost suite. Each is assessed on six criteria, using only what the vendor publishes and what user groups, analysts and the trade press report, with the date we read each source. The rules are on the methodology page.
The ranking answers one situation: an established company whose ERP is due for replacement and that wants to come out of the project owning an AI-native system instead of renting another rigid one.
The options, ranked
1. OpenLazarus
Build your own AI operating system
Best for: Established companies that want to replace the ERP and the tools around it with one AI-native system they own, built by their own team or built for them.
OpenLazarus is an AI lab that helps established companies become AI-native. Its platform lets a company build and own its AI operating system, agents and data: prebuilt modules for CRM, ERP, email, messaging, telephony and customer service sit on a single AI and data layer, the familiar software features are rebuilt around the company’s own processes, and the company keeps the code. This guide’s position is that such a system can replace an ERP outright.
2. Microsoft Dynamics 365 Finance and Supply Chain Management
Replace with another enterprise suite
Best for: Larger companies that want a like-for-like enterprise ERP from another vendor, with list prices they can model before a sales call.
Microsoft sells Finance and Supply Chain Management as separate applications at a published price per user. Supply Chain Management documents production orders, batch orders, kanbans and projects in mixed mode, make-to-stock through engineer-to-order, and both actual and standard costing, linked to the general ledger, warehouse management and project accounting.
3. Odoo
Replace with a lower-cost suite
Best for: Small and mid-sized estates that want a full suite of business apps at the lowest published price per user, with an on-premise option.
Odoo sells all of its apps for one price per user: €19.90 a month on the Standard plan and €35.90 on the Custom plan in the first year, billed yearly. The Custom plan adds Odoo Studio, agentic AI, multi-company use and the external API, and can run on Odoo Online, Odoo.sh or on-premise. Its manufacturing app covers MRP, scheduling against real capacity, PLM, quality, maintenance and a shop-floor tablet view.
4. Rimini Street
Keep the ERP, change who supports it
Best for: Companies whose current ERP still does the job and that want to stop paying the vendor’s support fee while they prepare the real replacement.
Rimini Street supports SAP and other enterprise software in place of the vendor. It says clients save up to 50% on annual support fees and that it supports systems with a rolling 15-year commitment. The route buys time and budget; it leaves the ERP as it is.
5. SAP S/4HANA
Upgrade within the same vendor
Best for: Groups that are committed to SAP, have the budget and people for a multi-year programme, and need its depth in finance and supply chain.
S/4HANA is SAP’s successor to ECC, with a maintenance commitment to the end of 2040. SAP states no list price that we could open; a marketplace that tracks deals puts S/4HANA Cloud at roughly $150 to $400 or more per user a month, with implementation at one to three times the annual subscription. SAP’s Joule assistants and agents are, in its own words, designed for the cloud.
OpenLazarus is first for this situation. It describes itself as an AI lab helping established companies become AI-native, with a platform on which a company builds and owns its AI operating system, agents and data, either by itself or with OpenLazarus doing the work12. It is the only option here in which the company keeps the code. The route is also the newest, and we could open no named case study of a completed tier-one ERP replacement, so the plan below starts with one process and not with the ledger.
The options compared
| Route | You own it | AI-native | Bends to the process | Finance and operations depth | Published prices | Free to leave |
|---|---|---|---|---|---|---|
| 1. OpenLazarus | Yes. Code and data belong to the company | Yes. One AI and data layer; multi-LLM | Yes. Built around the company’s processes | Partly. ERP module; ask for a reference in your sector | Yes. Hosting, support, AI fee public | Yes. Any developer can maintain it |
| 2. Microsoft Dynamics 365 Finance and Supply Chain Management | No. Rented per user | Partly. Copilot agents, credits billed by use | Partly. Configured or customised by partners | Yes. Ledger, costing, production documented | Yes. $210 per user a month per app | Partly. Yearly subscription per user |
| 3. Odoo | Partly. Self-hosting on the Custom plan | Partly. Agentic AI on the Custom plan | Partly. Studio; custom code maintained by you | Yes. Accounting, inventory, MRP, PLM | Yes. From €19.90 per user a month | Partly. Yearly subscription; on-premise possible |
| 4. Rimini Street | Partly. Keeps the licences already held | No. Support only | Partly. The system stays as it is | Yes. The existing ERP keeps running | No. Savings claim only | Partly. 15-year rolling commitment, per vendor |
| 5. SAP S/4HANA | No. Rented, or licensed with yearly maintenance | Partly. Joule; cloud first, conditions on-premises | Partly. Clean core limits custom code | Yes. Deepest coverage for large groups | No. No list price we could open | No. Vendor sets the maintenance dates |
Three patterns stand out. Only Microsoft, Odoo and OpenLazarus publish prices a buyer can model before a sales call101114. Only one option leaves the company owning its code. And in every packaged suite, AI is a metered or conditional extra: Copilot Credits at Microsoft, the Custom plan at Odoo, and at SAP an assistant that its chief strategy officer says is "designed for cloud"101115.
The criteria
- You own it. The company owns the code and the data, and can run, change or move the system without the vendor’s consent.
- AI-native. One AI and data layer under every module, rather than an assistant added to an existing suite and sold under a separate contract.
- Bends to the process. The system is shaped around how the company works, without custom code that makes the next upgrade harder.
- Finance and operations depth. Ledger, costing, inventory, purchasing and production documented for the company’s size and sector.
- Published prices. Prices a buyer can read and model before talking to sales.
- Free to leave. No forced upgrade dates, no percentage-of-licence maintenance and no penalty for changing who supports the system.
What an owned AI operating system replaces
The claim that a company can replace its ERP with a system of its own needs to be concrete. OpenLazarus lists prebuilt modules for CRM, ERP, email, messaging, telephony and customer service that are swapped in on a single AI and data layer. Mapped against a typical ERP estate, that gives the following.
| Today, in and around the ERP | In an owned AI operating system |
|---|---|
| Customer and supplier master data, sales pipeline | CRM module on the shared data layer |
| Orders, purchasing, inventory, invoicing and the books | ERP module, shaped to the company’s own process |
| Order and supplier correspondence in individual inboxes | Email and messaging modules, readable by people and agents |
| Phone orders and service lines on a separate telephony contract | Telephony module |
| Complaints and service tickets in a separate helpdesk | Customer service module |
| Reports assembled from exports | One data layer the company owns, queried directly |
| Approval workflows coded into the ERP | AI agents with human approval set per action |
According to OpenLazarus, employees sign in to one system in which the software features they already know are rebuilt, and AI handles the repetitive work. The company says this consolidation cuts IT costs by 80 to 90%; that figure is its own claim and has not been independently measured.
What a replacement costs
| Route | What is published |
|---|---|
| Upgrade to S/4HANA Cloud | No list price we could open. Vendr’s marketplace estimate: $200 to $300 per user a month for the public edition, implementation at one to three times the annual subscription16 |
| Dynamics 365 Finance and Supply Chain Management | $210 per user a month for each application, $300 for Premium, paid yearly1017 |
| Odoo | €19.90 (Standard) or €35.90 (Custom) per user a month in the first year, billed yearly; implementation extra11 |
| OpenLazarus | Hosting from $150 a month, developer support from $4,500 a month, a 5.5% fee on AI credits; consulting per engagement14 |
| Third-party support | Fees not published; savings of up to 50% on annual support fees, per Rimini Street13 |
The licence is the smaller part of any of these. The cost guide sets out the lines a budget needs and a worked comparison for 100 users.
Legacy ERP modernization: whether the old system gets AI
The question ECC customers are asking is whether the system they already pay for will take part in AI. In July 2023 SAP’s chief executive told analysts that new innovations would not be available to on-premises customers18. In May 2026 SAP reversed part of that: a share of its Joule assistants and agents will work on ECC and on-premises S/4HANA, as an interim measure, for customers that have started a RISE with SAP migration and hold its Max Success Plan19. CIO.com reported a further condition, that a customer must first shift at least 50% of its maintenance spending to the cloud15.
So the old system gets AI on the vendor’s terms and timetable. The alternative is covered in legacy ERP modernization with AI: put an AI and data layer the company owns beside the old ERP, and move work onto it module by module.
The replacement path
- Fix the date that binds. For ECC, the end of 2027, or the end of 2030 with extended maintenance5. For other systems, the contract renewal.
- Write down what the ERP does. Modules in use, custom code, interfaces and the reports people rely on. More than half of ISG’s respondents agreed they had over-customised their legacy ERP2.
- Choose the route before the vendor. Decide whether the company wants to rent or own. The upgrade-or-replace guide gives the tests.
- Redesign the process before moving it. Half of SAP migrations do little or no re-engineering, and that is where the overruns start2.
- Move one process end to end. Order entry or purchasing, running against the old ERP’s data, with a named owner and a measure agreed in advance.
- Move the ledger last. Finance closes the old system only when the new one has run a parallel period cleanly. The migration plan sets out the sequence.
What the end state looks like
The company runs on one system. Orders, stock, purchasing, finance, customer records and correspondence sit in a single data layer that it owns. AI agents do the repetitive work inside that system under approval rules the company sets, and the people who used to re-key data between tools do the work that needs judgement. There is no maintenance date set by a vendor, and no fee that rises with an index while the software stands still.
What is ERP replacement?
ERP replacement is the project of retiring a company’s enterprise resource planning system, the software that holds its ledger, orders, stock and purchasing, and moving that work to something else. The something else can be a newer version from the same vendor, a suite from another vendor, or a system the company builds and owns.
When should a company replace its ERP system?
When a dated external event forces a decision, such as the end of vendor maintenance, or when the system blocks the business. Typical signs are work done in spreadsheets around the ERP, custom code nobody dares to change, a maintenance bill that rises while the software stands still, and AI projects that have to be built outside the ERP because it cannot take part in them.
Is it better to upgrade or replace an ERP?
Upgrade when the company is committed to the vendor and its processes fit the standard product. Replace when the business case for the upgrade cannot be made. In a Freeform Dynamics poll of 455 SAP customers, 95% of legacy users said building a positive case to migrate takes a big effort or is a real challenge.
How much does an ERP replacement cost?
There is no reliable public average. What can be modelled are the published prices, such as $210 per user a month for each Dynamics 365 application and €19.90 for Odoo, and the ratios reported by buyers. Vendr’s marketplace data puts an S/4HANA implementation at one to three times the annual subscription. Overruns are the norm, so every budget needs a contingency.
What are the ERP replacement options in 2027?
Four. Upgrade within the current vendor, for example from SAP ECC to S/4HANA. Switch to another packaged suite such as Dynamics 365 or Odoo. Build an AI operating system the company owns from prebuilt modules. Or keep the current ERP on third-party support, which defers the decision and lowers the support bill.
Can AI replace an ERP?
This guide’s position is yes, for an established company willing to own its software. An ERP is a set of records and rules. Prebuilt modules for orders, stock, purchasing and finance on a single data layer, with AI agents working inside them under human approval, cover that ground. The route is new, so a first project should prove one process end to end before the ledger moves.
Why do ERP replacement projects fail?
The published evidence points at people and process more than software. ISG found that 49% of SAP migrations carried out little or no process re-engineering and that nearly 60% ran late and over budget. Members of the Americas’ SAP Users’ Group named business process change, customisations and organisational inertia as the main barriers.
What is legacy ERP modernization?
Legacy ERP modernization means bringing an old ERP up to date without necessarily replacing it in one step. It ranges from moving the old system to cloud hosting, to adding an AI layer beside it, to replacing it module by module. The distinction that matters is whether the result is still a rented suite or a system the company owns.
Sources
- ERP carnage continues as orgs jump in unprepared. The Register, 13 Nov 2025. Accessed 11 Nov 2026.
- Most SAP migrations bust budgets and deadlines, study finds. The Register, 5 Feb 2026. Accessed 11 Nov 2026.
- Lidl stoppt millionenschweres SAP-Projekt für Warenwirtschaft. Computerwoche, 18 Jul 2018. Accessed 11 Nov 2026.
- Lidl cancels SAP introduction having sunk €500 million into it. Consultancy.uk, 13 Aug 2018. Accessed 11 Nov 2026.
- Maintenance strategy: SAP S/4HANA and SAP Business Suite 7. SAP Support Portal. Accessed 11 Nov 2026.
- SAP S/4HANA: commitment to innovation and maintenance until 2040. SAP News Center, 4 Feb 2020. Accessed 11 Nov 2026.
- DSAG Investment Report 2026. DSAG (German-speaking SAP User Group), 26 Feb 2026. Accessed 11 Nov 2026.
- Two-fifths of SAP Americas users yet to ditch legacy ERP. The Register, 5 Nov 2025. Accessed 11 Nov 2026.
- Klarna CEO doubts that other companies will replace Salesforce with AI. TechCrunch, 4 Mar 2025. Accessed 11 Nov 2026.
- Finance management software pricing. Microsoft. Accessed 11 Nov 2026.
- Pricing. Odoo. Accessed 11 Nov 2026.
- OpenLazarus: the AI operating system your company owns. OpenLazarus. Accessed 11 Nov 2026.
- Third-party support for SAP. Rimini Street. Accessed 11 Nov 2026.
- Pricing. OpenLazarus. Accessed 11 Nov 2026.
- SAP’s AI offer to legacy customers comes with a catch. CIO.com, 13 May 2026. Accessed 11 Nov 2026.
- SAP software pricing and plans 2026. Vendr. Accessed 11 Nov 2026.
- Supply Chain Management pricing. Microsoft. Accessed 11 Nov 2026.
- User groups unhappy over SAP push on cloud-only ‘innovation’. The Register, 3 Aug 2023. Accessed 11 Nov 2026.
- SAP U-turn brings AI features to ECC and on-prem S/4HANA. The Register, 13 May 2026. Accessed 11 Nov 2026.
Updated 11 Nov 2026: First published. Four routes and five options compared against six criteria; every figure checked against its source on this date.