Why do ERP projects fail?
Every founder has heard the horror story from a peer. Here is what actually goes wrong — how often, in which order, what it looks like month by month, and what the companies that made it through did differently. And, because it is rarely said out loud: how much of it is the software’s fault.
Contents
The short answer
ERP projects fail because a company tries to do two hard things at once — change how it works, and change what it runs on — and plans only for the second. The software project has a budget, a timeline and a partner. The business change has none of those. It has a steering committee that meets monthly, key users who are “involved as needed”, and data that will be cleaned “later”.
The specific causes are remarkably consistent across companies, industries and decades: processes nobody defined, requirements that grew after the contract, data that was never cleaned, a standard system bent to fit old habits, the daily users left out of the room, decisions starved for months, and a go-live treated as a date rather than a state. Every famous disaster is three or four of these at the same time, and every one of them was visible months before it happened.
What is said less often: these are all failures of translation — of the work needed to fit a rigid system to a real company, by hand, under time pressure. That is a property of how ERP has been built, and it is worth separating what the customer got wrong from what the architecture made likely. This article does both.
In one sentence
ERP projects fail when a company changes how it works and what it runs on at the same time — and only plans for the second.
What “failure” means — and how often it happens
You will read that “50 to 75 percent of ERP projects fail.” You will also read that most companies are satisfied with their ERP. Both are true, because “failure” means four different things, and the numbers change with the definition.
≈ 30 %
finish over budget, and about 22 percent finish late — the largest annual survey of ERP implementations, 2026 edition. Additional scope discovered mid-project is the leading cause.
> 70 %
of recently implemented ERP initiatives will fail to fully meet their original goals by 2027, according to Gartner — and as many as 25 percent could fail catastrophically.
1 in 5
fails when failure is defined by benefits: delivering less than 70 percent of what the business case promised, across studies that use that measure.
1 in 6
large IT projects is a “black swan” — the Oxford study of 1,471 projects found that one in six ran over budget by an average of 200 percent, with schedule overruns of almost 70 percent.
Read together, the numbers say something more useful than any single one: the normal ERP project is somewhat late, somewhat over budget, and delivers less than the slide deck said. Outright catastrophe — the abandoned system, the company that cannot ship — is rarer, perhaps one project in five or six. But the everyday failure, the project that goes live and quietly does not deliver, is the majority experience. That is the one this article is mostly about, because it is the one you will not read about in the news.
The famous ones, and what each teaches
The disasters that made the papers are worth a minute each — not for the schadenfreude, but because every one of them is a small company’s mistake at a scale where it became visible.
Lidl
2011–2018Abandoned its SAP programme after about seven years and a reported EUR 500 million. Lidl valued stock at purchase price; the standard valued it at retail price. Neither side gave way, and the system was customised until it could not be finished.
LessonA single non-negotiable habit can sink the whole project. Decide before you sign which of your ways of working are truly an advantage — and give up the rest.
Hershey
1999Went live with ERP, CRM and planning systems in one big bang, in July, just before the Halloween order peak. Orders worth about USD 100 million could not be shipped; the share price fell by a third.
LessonNever go live at the peak of your season, and never with everything at once. Go-live is the riskiest day of the project; choose the calmest one.
Revlon
2018A new ERP at its main US plant disrupted manufacturing and shipping so badly that the company could not fulfil about USD 64 million of orders in one quarter and faced shareholder lawsuits.
LessonA go-live without a working fallback turns a software problem into a customer problem within days. Parallel runs and rollback plans are not luxuries.
Haribo
2018A SAP go-live led to supply problems severe enough that its best-known product was missing from shop shelves; sales reportedly fell by about a quarter during the disruption.
LessonThe warehouse is where data quality becomes physical. Stock that was wrong in the old system arrives wrong in the new one — and now everyone trusts it.
Birmingham City Council
2022–Replaced its SAP system with Oracle; the budget grew from under GBP 20 million to well over GBP 100 million, the council lost the ability to produce reliable accounts, and the failure contributed to its financial emergency.
LessonCustomising a standard system to reproduce the old one, with the users’ requirements gathered too late, produces a system that costs more than the one it replaced and does less.
Notice that none of these companies lacked money, consultants or software brand names. What they lacked was a decision about how they wanted to work, a go-live that was a state rather than a date, and someone willing to say “not yet” to a steering committee.
The seven causes, in the order they strike
Failure is rarely one thing. It is a sequence, and the sequence is so regular that you can date each cause to a phase of the project.
1. Nobody decided how the business should work
The project starts with “implement the system” instead of “this is how an order should flow through the company from now on.” The analysis phase then becomes the place where that decision is supposed to happen — with consultants on the meter, in workshops where three departments each defend their version. Software multiplies clarity and chaos with equal enthusiasm; if the process is undecided, the system faithfully implements the argument.
2. The requirements were the vendor’s, and then they grew
Two failure modes with one root. Either the requirements came from the vendor’s template — a catalogue of their features phrased as your needs — or they were never written down at all, and are discovered in month six as “but we obviously need that.” Additional scope found mid-project is the single most cited cause of budget overruns. A twenty-page requirements document, written before the first demo, is the cheapest insurance in the whole project; we explain how in How do you choose the right ERP?
3. The data was going to be cleaned “later”
Every project discovers its data in the first migration test, and every project underestimates what it finds: duplicate customers, article numbers in four formats, prices that live in someone’s head, the fields repurposed in 2019. Cleaning is assigned to “the business”, which is busy running the business, and postponed until it collides with go-live. Then the new system starts life with the old system’s errors — and, unlike the old system, everyone trusts it.
4. The standard was bent to fit old habits
The instinct is to make the new system do exactly what the old one did, plus the fixes. Each customisation is approved to avoid a fight, each is small, and together they are the budget — and the upgrade problem for the next decade. Lidl is the extreme case; the ordinary case is a mid-sized company that spent 40 percent of its implementation coding around the standard and is now stuck on a version from 2021 because the customisations would break.
5. The people who use it every day were not in the room
Surveys have named change management as the number one reason for ERP failure for twenty years, and it has not changed because the underlying mistake has not changed: the project is run by management and IT, and the people who will spend eight hours a day in the system meet it at training, two weeks before go-live. They were never asked where the system had to be fast, what the exceptions were, or what they would do when it did not fit. So they do what people do — they route around it, and the shadow spreadsheets return.
6. Decisions starved, and the project lead had another job
Projects stall on the customer side far more often than on the vendor side. A steering committee that meets monthly turns a four-month project into an eight-month one; a project lead with the job on top of their real one answers questions on Fridays. Meanwhile the consultants bill, the team waits, and the momentum that carried the kick-off drains away. Every project needs one owner with the time and the authority to decide within days — and most SME projects do not have one, because the person who could do it is the CEO, and the CEO is busy.
7. Go-live was a date, not a state
The date was announced to the company in month three. By month nine the plan serves the date: testing is compressed, training shortened, the parallel run cancelled, the peak season ignored. Go-live should be a set of conditions — these tests passed, this data reconciled, these people trained, this fallback ready — and if the conditions are not met, the date moves. Every company in the previous section went live on a date.
Anatomy of a failing project
Put the seven causes on a calendar and you get the same story, in almost every company that tells it. If you are in a project now, find your month.
Month 0
Kick-off
Everyone is optimistic. The scope is “what we discussed”. The project lead has the job on top of their real one. Key users are “involved as needed”.
Month 2
The analysis grows
Workshops reveal that three departments describe the same process three ways. Nobody decides which is right; the consultants document all three. The requirements double.
Month 4
The data is discovered
The migration test fails on duplicates, empty fields and article numbers in four formats. Cleaning is assigned to “the business”, which has no time. It is postponed to “before go-live”.
Month 6
The change requests begin
The standard does not do it the way the old system did. The first customisations are approved to avoid a fight. Each one is small. Together they are the budget.
Month 9
The date becomes the goal
The steering committee has already announced go-live to the company. Testing is compressed, training is shortened, the parallel run is cancelled. The plan now serves the date.
Month 12
Go-live
Orders take three times as long. Stock figures are wrong because the migration ran on dirty data. The warehouse works from printouts. Customers notice within a week.
Month 15
The workarounds set
Shadow spreadsheets return. Key users quietly rebuild the old process outside the system. The change requests needed to fix it are unaffordable, so they are not raised.
Month 24
The version freeze
Upgrades are skipped because the customisations would break. The system is declared a success in a slide deck, and everyone agrees never to touch it again.
The last line is the important one. Most failed ERP projects are never called failures. They go live, they are declared a success, and the company spends the next decade paying for a system it works around. That is what “70 percent do not fully meet their goals” looks like from the inside.
Early-warning signs
Every cause above is visible months before it does damage. These are the signs, and each one has a phase where it can still be fixed cheaply.
What the survivors did differently
The companies whose projects worked did not have better software or more money. Their projects are boring to describe, because they did a handful of unglamorous things, in the right order, and refused to skip them under pressure.
None of this is secret. It is in every implementation methodology every vendor publishes. The reason it is skipped is that every item costs time before go-live, and the pressure in an ERP project always points toward the date. The survivors are the companies where someone had the authority to resist that pressure — and used it.
Whose failure is it?
Ask a vendor why ERP projects fail and you will hear the seven causes above, all of them on the customer’s side of the table: undefined processes, slow decisions, dirty data, absent users, scope creep. Ask a customer and you will hear about consultants who did not understand the business, a system that could not do the obvious thing, and a price that doubled. Both are describing the same project, and both are right — which should tell you something about the project.
Look at the seven causes again. Every one of them is a failure of translation: of the work required to fit a rigid, generic system to a specific, living company, by hand, through consultants, under a deadline. The customer’s process has to be decided in advance because the system cannot bend later. The data has to be perfect before migration because the system cannot understand it. The users have to be trained because the system will not adapt to them. Every deviation has to be coded because the standard is fixed. And every one of those steps costs consulting days, which is why the pressure toward the date never lets up.
The industry has spent forty years describing that as the customer’s job and the customer’s failure. It is more honest to say that the architecture made the failure likely and then charged for the attempt. The customer mistakes are real. But they are mistakes that a system which could adapt to the company — instead of the other way round — would make far less consequential. That is not a defence of slow decisions or dirty data. It is a description of why the same decisions and the same data sink one project and barely dent another.
How AI changes the odds
If most failure is translation, then a system that needs less translation fails less. That is the honest case for AI-native ERP, and it is worth stating precisely rather than as a slogan.
Three of the seven causes are directly about translation, and they shrink. Customisation stops being a coding project when the people who use the system can reshape it in plain language — a field, a workflow, a view — and change it again next month, so the fear of cementing the wrong process loses its force. Data cleaning stops being a three-month sprint the business has no time for when migration is assisted by a system that understands what the old data means and asks about the rest. Scope creep stops being a budget catastrophe when the discovered requirement is an afternoon’s change rather than a change request at a day rate.
Four of the seven do not disappear, and it would be dishonest to claim they do. A company still has to decide how it wants to work. Someone still has to own the project and decide within days. The people who use the system still have to be in the room — though a system that adapts to them makes their involvement productive rather than defensive. And go-live is still a state, not a date. What changes is the cost of every mistake: in a system that adapts, an undecided process is a week of iteration, not a six-figure customisation, and a late discovery is a Tuesday, not a crisis.
Tenebrax is building the ERP that fails less because it translates less — AI-native from the ground up, reshaped by the people who use it instead of coded by consultants, migrated with AI instead of cleaned by hand. No implementation marathon. No change-request fees. No migration prison.
Frequently asked questions
Why do ERP implementations fail?
Because a company tries to change how it works and what software it runs at the same time, and plans only for the second. The recurring causes are processes nobody defined, requirements that grew after the contract, data that was going to be cleaned “later”, a standard system bent to fit old habits, the people who use it daily left out of the project, decisions that took months, and a go-live treated as a date instead of a state. Almost every famous disaster is three or four of these at once.
What percentage of ERP projects fail?
It depends on what you call failure. Roughly 30 percent of projects finish over budget and about 22 percent late, according to the largest annual survey of implementations. Gartner expects more than 70 percent of recent implementations to fall short of their original goals, and up to a quarter to fail outright. Measured by benefits delivered — less than 70 percent of what was promised — about one in five fails. Whichever definition you choose, the honest summary is: a normal project is late, over budget, and delivers less than the business case said.
What is the most common reason ERP projects fail?
Surveys name change management — people not adopting the new system — as the number one reason, and additional scope discovered mid-project as the leading cause of budget overruns. Behind both sits the same root: the distance between how the company actually works and what the software does in its standard, which somebody has to close by hand, at a day rate, under time pressure.
What was the biggest ERP failure?
By money, Lidl: the retailer abandoned its SAP programme in 2018 after about seven years and a reported EUR 500 million, largely because its way of valuing stock did not match the system’s standard and neither side would give way. By consequences, Birmingham City Council, whose Oracle replacement grew from a budget of under GBP 20 million to well over GBP 100 million and left the council unable to produce reliable accounts. By fame, Hershey in 1999, which went live before Halloween and could not ship USD 100 million of orders.
How do you prevent an ERP project from failing?
Decide how the business should work before choosing software. Keep the scope fixed and the requirements short. Clean the data first, not later. Adopt the standard and write down what you will not customise. Put the people who will use the system on the project with real time — a third of their week, not evenings. Name one owner with authority to decide within days. Define go-live as a set of tests passed, not a date, and never go live at the peak of your season. Budget 15 percent contingency before you need it.
Is ERP failure the vendor’s fault or the customer’s?
Both, in a way that lets each blame the other. The customer failures — undefined processes, slow decisions, dirty data, absent key users — are real. But they are failures of the translation work a rigid system demands: an architecture that has to be configured by consultants and coded to fit any deviation makes every one of those mistakes more likely and more expensive. The industry has spent forty years calling that the customer’s problem.
Can a failing ERP project be rescued?
Usually, if it is stopped early enough. The standard rescue is a scope freeze, a return to the standard for everything that was being customised, a data-cleaning sprint owned by the business, a phased rollout instead of the big bang, and go-live criteria written down and tested. What rarely works is adding more consultants to a project whose problem was never consulting capacity.