S/4HANA Migration

S/4HANA Migration and Security Revalidation

S/4HANA migration is not just a platform upgrade, it is a control reset point. User access, privileged paths, service accounts, batch jobs, and system integrations often need to be rechecked because legacy roles and trust assumptions rarely survive the move intact.

Why Migration Changes the Access Model

SAP ERP estates often accrete custom roles, technical users, and indirect access paths over many years. During migration, organisations typically consolidate transactions, redesign authorisation objects, and map old permissions to new business processes in S/4HANA, which means the access model should be treated as a design exercise, not a lift-and-shift exercise.

This is also where the boundary between business continuity and security becomes visible. If old access is preserved too loosely, the new environment can inherit excessive privilege, dormant accounts, and unreviewed exceptions; if access is cut back too aggressively, finance and operations can fail in production.

Controls That Need Revalidation During Migration

The most important checks are authentication, authorisation, logging, and segregation of duties. Teams should confirm that users still authenticate through approved paths, that roles still reflect job function, that service accounts still use the minimum access needed, and that audit logging remains sufficient to detect misuse after cutover.

Privileged access deserves special attention because migration work often creates temporary elevation, firefighter-style emergency access, and urgent transport changes. Those shortcuts may be necessary for delivery, but they should be time-bound and removed when the migration stabilises. NHIMG’s SAP Identity and Access Security Guide is a useful reference for role design, emergency access, and segregation-of-duties issues that commonly surface in SAP programmes.

Integration, Data Flow, and Operational Continuity

Migration affects more than end users. Interfaces, RFC users, background jobs, APIs, and downstream analytics tools may depend on technical credentials and specific trust relationships that are easy to miss in project plans. If those connections are not inventoried and revalidated, the result is often broken business flows, hidden overprivilege, or insecure temporary workarounds.

Security teams should pay particular attention to connections that are not used interactively, because those paths are commonly underdocumented yet highly privileged. The same is true for read-only access that quietly became write access over time, or for third-party connections that were never formally revisited after the original implementation.

What Good Migration Governance Looks Like

Strong governance treats the migration as an opportunity to remove access debt. That means confirming ownership of every critical role and technical identity, reviewing exceptions before go-live, and validating that the target-state access model matches the redesigned SAP processes rather than the legacy ERP structure.

Practitioners should also plan for post-cutover review, because migration defects often show up first as failed transactions, unexpected authorisations, or audit-log anomalies. A short stabilisation window with explicit monitoring is usually more valuable than assuming the first successful cutover means the security model is finished.

Related resources from NHI Mgmt Group

• How should security teams govern SAP access during an S/4HANA migration?
• Who should own control readiness during an SAP S/4HANA migration?
• How should security teams plan an SAP ECC to S/4HANA migration without disrupting business operations?
• What breaks when SAP data is not classified before migration to S/4HANA?