Nearly 60% of SAP S/4HANA migration projects exceed budget and timeline, according to ISG research published this month. The survey of 200 senior decision-makers reveals a pattern: weak governance matters more than technical complexity.
The numbers are stark. Fewer than one in five organizations actually re-implement processes during migration. Nearly half (49%) preserve legacy processes and data, choosing what ISG calls a "brownfield" approach. Another 48% mix brownfield with greenfield strategies, what the industry optimistically terms "bluefield."
This is significant because 2027 marks the end of mainstream support for SAP ECC, the legacy platform still running at thousands of large enterprises. Gartner data shows 39% of SAP's 35,000 ECC customers worldwide hadn't migrated as of Q4 2024, nearly a decade after S/4HANA launched.
Michael Dornan, ISG principal analyst, points to a consistent failure mode: "A lot of them are trying to do this quickly, a lift-and-shift as fast and cheap as possible. This group often underestimated the complexity, scope and the constraints they have."
The research identifies a fundamental tension. Organizations cite maintenance deadlines as the primary driver, using migration as a compliance exercise. But 34% admitted they've over-customized legacy ERP to the point where standardization now feels risky to the business.
What this means in practice: enterprises treating migration as technical compliance rather than strategic transformation are significantly more likely to experience cost overruns and struggle to realize ROI, particularly for AI and automation capabilities that require clean data and standardized processes.
Market conditions are improving for new migrants. Consultant demand is decreasing as over half of companies complete transitions, reducing bottlenecks and costs. SAP has also introduced extended support options beyond 2030 for customers who commit to migration commercials.
The pattern is clear: hard choices about process standardization and data governance delayed during planning surface as costly rework after go-live. History suggests the organizations shipping now are learning this lesson the expensive way.