Most S/4HANA upgrade projects don’t fail at go-live. They fail months earlier, in decisions that looked harmless at the time: a custom code remediation plan that skipped impact analysis, a Fiori rollout treated as a UI refresh instead of a process redesign, a cutover schedule built around the system instead of the business calendar.

The numbers back this up. Panorama Consulting’s 2024 ERP Report found that a third of ERP implementations exceeded their planned budget, with over 5% blowing past it significantly and the leading causes weren’t software licensing, but underestimated staffing, organizational complexity, and unplanned technology requirements. Separate industry research has long shown that more than half of ERP projects run over schedule, and a meaningful share of organizations realize less than half of the benefits they originally modeled. For S/4HANA specifically, the stakes are higher: SAP’s compatibility packs and pre-2020 release support windows are closing out through 2025, which means many “upgrades” are really forced migrations under time pressure exactly the conditions that produce budget and benefit shortfalls.

Technically, the failure pattern is consistent. Teams run the SAP Readiness Check and Simplification Item-Check, treat a clean report as a green light, and underweight three things that actually determine outcomes: custom code that wasn’t built for S/4HANA’s data model, master data quality that was never enforced in ECC, and the change management needed for users to adopt Fiori-based, role-driven workflows instead of transaction-code habits. None of that shows up in a technical readiness score. All of it shows up in go-live.

This is where methodology not tooling makes the difference. Lean IT applies a Lean implementation discipline to SAP programs: scoping the custom code landscape before the technical upgrade starts, sequencing data cleansing as a workstream with its own owner and exit criteria, and running cutover rehearsals against business-critical processes rather than generic test scripts. Organizations that follow this kind of structured, waste-eliminating governance consistently report materially shorter remediation cycles, fewer post-go-live emergency fixes, and faster time-to-value on the Fiori and analytics capabilities they paid for because the project plan accounts for where S/4HANA programs actually break, not just where SAP’s tooling checks for readiness.

If your upgrade is already scheduled, or you’re still deciding whether to upgrade or re-implement, the gap between a readiness checklist and an actual delivery plan is where most budget overruns are quietly created. Lean IT has built its practice specifically around closing that gap bringing the technical rigor of SAP’s Activate methodology together with Lean principles that keep scope honest and timelines real.

Don’t let your upgrade become another statistic. Schedule a consultation call with Lean IT today, and let’s pressure-test your S/4HANA roadmap before it becomes a budget line you have to explain.