What Actually Ends, and What Remains
Mainstream maintenance for SAP ECC 6.0 ends on December 31, 2027. Extended maintenance is available from 2028 through 2030, but it adds 2 percentage points to the existing rate — moving annual support from roughly 22% of license value to 24%. After 2030, systems fall back to customer-specific maintenance, where new regulatory updates and security patches are no longer guaranteed. S/4HANA, by contrast, has mainstream maintenance committed through 2040.
The most common misconception is that the system simply stops working after 2027. It does not. ECC keeps running. The real exposure lies elsewhere: tax law amendments, e-invoicing format changes, and accounting standard updates no longer arrive as standard patches, and when a vulnerability is disclosed, there is no vendor fix to wait for. The issue is a compliance and security gap, not a technical shutdown. The remaining time should be read as a decision deadline, not a system lifespan.
Comparing the Four Options
1. Migrating to S/4HANA
2. Third-Party Maintenance
This cuts annual support fees roughly in half and buys two to five years of decision time. The trade-off is losing access to new SAP patches and features, and the possibility of being charged back-maintenance if you later return to SAP support. Confirm those terms before signing.
3. Replacing with a Domestic ERP
Total cost of ownership drops sharply, and local tax and e-invoicing compliance is a genuine strength. But functional gaps appear quickly for companies with multi-currency consolidation, multiple legal entities, or global supply chain requirements.
4. Partial In-House Development
Keep the ERP core and rebuild only the surrounding processes in-house. Initial cost is the lowest of the four, but the quality of the integration design determines whether it succeeds.
Diagnostics That Determine Migration Scope
The starting point is measured data from your current system, not a vendor proposal.
Reducing Risk Through Phased Migration
A big-bang cutover tends to break schedule and budget together. The practical alternative is to peel off peripheral processes first. Areas with many users but simple accounting logic — purchase requisitions, warehouse receiving and shipping, shop-floor data entry — can move to lightweight systems early, reducing both ECC load and custom-development dependency at once.
From there, keeping the ERP core in place while moving only extension areas to the cloud is an effective hybrid pattern. Leave finance and costing, which are tied directly to regulation, until last, and separate out supplier portals, mobile approvals, and dashboards first. By the time the core migration begins, the scope left to move has already shrunk.
When Internal Capacity Is Thin
In mid-sized companies where one or two people own the ERP, bundling the migration project and ongoing operations into a single contract creates a support vacuum the moment the project closes. It is safer to procure the build and the maintenance (SM) contract separately, with operations structured on an adjustable monthly basis.
POLYGLOTSOFT supports this path incrementally — from interface diagnostics through building separated lightweight systems — based on hands-on experience with legacy ERP integration and surrounding systems. After delivery, subscription-based SM starting at ₩90,000 per month covers incident response and ongoing improvements, so operational continuity does not depend on hiring dedicated staff. If you would like to start by assessing your ECC migration scope, we would be glad to talk.