7 min read

S/4HANA migration dominates the IT agenda. Yet while companies invest billions in new systems, the old ones often remain untouched. This costs money, creates compliance risks, and ties up resources needed elsewhere. Data decommissioning solves this problem-but is systematically overlooked in most migration projects.

Key Takeaways

• Nearly half of German-speaking SAP users plan to continue operating their ECC systems beyond 2027, despite the end of mainstream support (DSAG survey, February 2026).
• Legacy system maintenance typically consumes 15 percent of the IT budget-on systems no longer operationally required.
• There is virtually no independent editorial content on data decommissioning in the German-speaking region. The topic remains underreported, even as pressure to act intensifies.
• Modern data archiving solutions enable audit-proof access to legacy data via SaaS-without needing to keep source systems running.

SAP ECC: Support Ends, Systems Remain

SAP has clearly communicated its timeline. Mainstream support for ECC releases EHP 0 through 5 already expired at the end of 2025. Releases EHP 6 through 8 will follow suit by the end of 2027. After that, only Extended Maintenance remains-available at a 9 percent premium over previous license costs.

Reality diverges sharply from the roadmap. According to a DSAG survey conducted in February 2026, nearly half of German-speaking SAP users plan to continue operating their ECC systems beyond 2027. The reasons are understandable: S/4HANA migrations take longer than planned, cost more than budgeted, and tie up the best talent on the team.

What’s often overlooked: Even companies that successfully migrate to S/4HANA frequently leave their legacy systems running. Operational use may be complete, but historical data must remain accessible. German commercial law (GoBD) mandates audit-proof access for up to ten years. GDPR deletion deadlines must still be met. And in M&A transactions, warranty claims can require access to legacy data years later.

The Forgotten Step: What Happens After Go-Live

An S/4HANA migration consists of two halves. The first half gets the attention, the budget, and the project teams: data migration, customization, testing, go-live. The second half is postponed: What happens to the legacy systems?

In practice, this means ECC instances, Navision systems, AS/400 applications, and mainframe apps remain running in the data center. They consume licenses, server resources, and administrative capacity. Patches must still be applied-even though no user actively works with them anymore. Expertise for these systems dwindles, while costs remain constant.

IT leaders know this problem well. But there’s rarely a dedicated budget for “shutting down legacy systems.” Decommissioning never appears on roadmaps because it delivers no new features and doesn’t fill out a business case slide. Yet the math is simple: Every euro not spent maintaining dead systems becomes available for innovation.

Three Typical Scenarios for Data Decommissioning

Data decommissioning addresses situations that IT departments in the DACH region (Germany, Austria, Switzerland) regularly encounter. Here are three real-world scenarios.

Scenario 1: Post-Migration. A company has completed its transformation to S/4HANA while simultaneously consolidating multiple legacy systems. Operational data from the past two years has been migrated. However, historical data from ECC and Navision must remain accessible, as auditors, tax advisors, and internal compliance teams still require it. Instead of continuing to operate both legacy systems, the data is transferred to an archival system. The source systems are then decommissioned.

Scenario 2: M&A Transaction. Company A sells a business unit to Company B. Operational data is migrated, but both parties must retain access to historical records-for warranty claims, legal obligations, and compliance with Germany’s GoBD (principles for proper recordkeeping of digital documents). Creating a full system copy would be costly. A leaner alternative: a compliant archival tool that preserves data integrity while maintaining logical access.

Scenario 3: Data Center Shutdown. Servers must be removed from the data center by year-end. Business-critical historical data resides on an AS/400 and a mainframe-data that cannot be deleted due to regulatory requirements. The applications running on them aren’t cloud-compatible. Solution: export the data, store it in a cloud-based archival tool, and power down the legacy hardware.

How Modern Decommissioning Works

The approach has evolved significantly in recent years. Previously, the standard was SAP’s native archiving via ILM or running read-only copies. Both methods have limitations: ILM is complex, requires ongoing SAP licenses, and covers only SAP data. Read-only copies still need patching and administrative upkeep.

Modern historical data platforms-like Historia from SDD Group-take a different path. Data is exported from the source system and stored in a cloud-based data store. Access is provided through a web application that replicates the business logic of the retired system. Users see the data in its familiar structure-even though the original system no longer exists.

Pricing is based on storage volume, not user count. Unlimited users, single sign-on, role-based access control. For IT departments, this means: no recurring license fees for legacy systems, zero administrative overhead, and no patch management for end-of-life software.

A retention manager ensures GDPR-mandated deletion deadlines are met, automatically removing or anonymizing data once retention periods expire. In regulated industries like financial services and pharma, supervisory authorities actively audit compliance.

Why This Topic Belongs on Your Agenda Now

The convergence of expiring SAP support, rising cloud costs, and tightening compliance requirements is creating pressure that can’t be ignored. Companies continuing to run ECC systems beyond 2027 in Extended Maintenance mode will pay 9 percent more-for a system that receives no new features.

At the same time, regulatory demands are intensifying. GoBD-compliant data retention, GDPR-mandated deletion obligations, and sector-specific rules like DORA in finance now make structured data archiving non-negotiable. “Just keep it running” is not a compliance strategy.

For IT leaders and CIOs, decommissioning isn’t glamorous. It doesn’t deliver innovation, AI capabilities, or a prestige project for the next board presentation. But it frees up budget, reduces risk, and simplifies the IT landscape-precisely the priorities that will define success twelve months from now.

Frequently Asked Questions

What is Data Decommissioning?

Data decommissioning refers to the structured process of shutting down legacy systems and migrating their data into a separate archival or historical storage system. The goal is to preserve access to historical data without needing to keep the source system operational.

How long does a typical decommissioning project take?

Implementation time depends on the complexity of the source system and data volume. For standardized SAP environments, projects can be completed in a few weeks. More complex landscapes involving multiple legacy systems may require three to six months.

What does it cost to simply keep legacy systems running?

Industry estimates suggest legacy system maintenance consumes around 15 percent of IT budgets. Additional indirect costs include administrative labor, security risks from unpatched systems, and opportunity costs tied up in maintaining outdated infrastructure.

Is Data Decommissioning only relevant for SAP systems?

No. Archiving solutions like Historia support not only SAP but also non-SAP systems such as Navision, AS/400 applications, mainframe platforms, and other legacy databases. The approach is system-agnostic.

Which compliance requirements does decommissioning address?

Germany’s GoBD (Generally Accepted Principles of Proper Accounting) mandates audit-proof access to business-relevant data for up to ten years. The GDPR requires deletion of personal data once its processing purpose expires. Sector-specific regulations like DORA in finance further tighten these obligations. Modern archiving platforms address all three areas comprehensively.

Source, cover image: FLUX.2 / Cloudflare Workers AI