Why so many S/4HANA go-lives go wrong and what to do before yours does

There's a moment every project team dreads. Go-live day arrives, the system switches on, and within hours it's clear something is badly wrong. Orders aren't processing. Financial reports are producing incorrect figures. The warehouse module that worked perfectly in testing is throwing errors in production.

This isn't a hypothetical.

Real-World Case · November 2025

In the first week of November 2025, Tennant Company a Minnesota based global manufacturer with approximately $1.2 billion in annual revenue cut over to a new company-wide SAP cloud ERP system in North America. Within days, the business could no longer reliably process or ship customer orders.

Tennant ERP Impact — Embeddable Cards
~$30M
Lost net sales, Q4 2025
Tennant 8-K · Feb 2026
>$20M
Unplanned remediation costs, 2026
BFA Law / GlobeNewswire
−23.4%
Stock price, single session · 24 Feb 2026
BFA Law / GlobeNewswire
Tennant — What Failed at Go-Live
📦
Order management & fulfillment
Unable to process or ship customer orders. Customers received no reliable shipment visibility throughout November 2025.
Tennant 8-K · p.5
🏭
Manufacturing scheduling & inventory visibility
Disruptions acute in Parts, Consumables & Service. Required a two-week factory shutdown in January 2026 for a full physical inventory count.
Tennant 8-K · p.5, p.8
⚙️
Transaction processing throughput
Slower processing caused cascading delays across core workflows. Required cross-functional recovery teams and interim workarounds to stabilise.
Tennant 8-K · p.5

Tennant is not an outlier. It is a pattern.

The numbers behind the problem

S/4HANA migrations are among the most complex programmes an enterprise can undertake. A 2025 study by management consultancy Horváth, covering 200 companies across Europe and the US, found that problems are not the exception, they are the rule.

>60% of companies experience significant deviations in budget, schedule, and result quality during S/4HANA migration. When you break that headline number down, each dimension tells its own story:

S/4HANA Migration Stats — Embeddable Cards
92%
did not complete on schedule - only 8% of companies finished their migration on time
Horváth · CIO Mar 2025
>60%
exceeded their planned budget, significantly so in over a quarter of cases
Horváth · CIO Mar 2025
65%
identified severe to very severe quality deficiencies after completing the migration
Horváth · CIO Mar 2025

When you look at what drives those outcomes, inadequate end-to-end testing appears consistently near the top of every post-mortem.

Why manual testing isn't enough

An S/4HANA implementation touches everything: procurement, inventory, finance, production, HR, reporting. Every area has interconnected workflows. A change made to fix one process can silently break another and in a complex SAP landscape, the number of scenarios that need validating before go-live is enormous.

Manual testing cannot keep pace with that complexity. Business teams are already stretched running day-to-day operations while contributing to the implementation. Test cycles run long. Coverage is incomplete. By the time testers work through the backlog, the system has changed again.

Pull Quote — ASSUR4NCE
"

Go/no-go decisions get made on gut feel rather than evidence. Stakeholders ask "are we ready?" and the honest answer is "we think so." That is not a foundation for a safe go-live.

The pressure isn't easing

According to research by Precisely and ASUG published in November 2025, 59% of companies are now fully or partially live on S/4HANA up 13 percentage points from 2024, as organisations race to meet SAP's 2027 mainstream support deadline. That deadline is concentrating significant demand into a short window. Implementation partners are busy, experienced SAP resources are stretched, and organisations still mid-migration are under pressure to accelerate which is precisely when testing shortcuts get taken.

The irony is that cutting corners on QA doesn't save time. It borrows it, at a punishing interest rate. Every defect caught in testing costs a fraction of what it costs to fix in production.

What structured QA actually changes

The alternative to hoping for the best is building confidence through evidence. Structured, automated quality assurance means running comprehensive regression tests continuously throughout the migration using Tricentis Tosca, not just at the end. It means knowing, with data, which business processes are passing and which aren't. It means walking into a go/no-go decision with a dashboard, not a feeling.

For an S/4HANA programme, that typically involves:

QA List — ASSUR4NCE
  • Risk-based test coverage

    Prioritising the processes that carry the most business risk, so testing effort goes where it matters most.

  • Automated regression

    Running the same tests repeatedly with Tricentis Tosca across every system change, without adding weeks of manual effort.

  • End-to-end process validation

    Testing complete workflows across SAP modules, not just individual transactions in isolation.

  • Release readiness reporting

    Giving leadership a clear, objective view of where the programme stands before go-live — replacing gut feel with data.

S/4HANA migrations will always be demanding. But there is a meaningful difference between a programme that arrives at go-live with evidence-based confidence and one that arrives with crossed fingers.
CTA — ASSUR4NCE
ASSUR4NCE by COGO Consulting

Ready to go live with confidence?

Talk to us about building a QA strategy using Tricentis for your S/4HANA migration before it becomes a problem.

Contact COGO Consulting
Sources — ASSUR4NCE
[1]
Horváth S/4HANA Migration Study, Q1 2025 via CIO · March 2025 · 200 companies, DACH + Northern/Eastern Europe + US Umbrella >60% figure · 92% schedule overrun / only 8% on time · >60% budget exceeded · 65% quality deficiencies cio.com
[2]
ASUG SAP S/4HANA Journeys Research 2024 Americas SAP Users Group · July 2024 · 208 ASUG members 49% of companies already live exceeded original budgets — up 17pp from 2023 asug.com
[3]
Transforming SAP Processes Through Automation: 2026 Trends and Challenges Precisely & ASUG · November 2025 59% of companies fully or partially live on S/4HANA — up 13pp from 2024 precisely.com
[4]
Tennant Company Form 8-K — Q4 & FY 2025 Results SEC filing · February 23, 2026 FY 2025 revenue $1,203.5M · ~$30M net sales impact Q4 · ~$22M Adj. EBITDA impact Q4 · ERP go-live November 2025 · operational failures: order management, manufacturing scheduling, inventory visibility SEC / tennantco.com
[5]
BFA Law / GlobeNewswire — TNC Securities Investigation GlobeNewswire · March–May 2026 Stock drop 23.4% ($82.30 → $63.02, Feb 24 2026) · >$20M unplanned remediation 2026 vs ~$5M planned · ~$344M market cap calculated: 17,846,681 shares × $19.28 drop globenewswire.com
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