Häufig gestellte Fragen
How long does a typical ERP migration take?
In the mid-market, around 9 to 18 months are common depending on complexity and depth of customisation, while corporate groups with many sites and rollout waves often need 18 to 36 months or longer. Cloud standard solutions with little customising, by contrast, can go live in as little as roughly 4 to 6 months. Experience shows that a large share of the project time goes into conceptual design, customising and data preparation, while testing, training and the actual roll-out take up the rest. Realistic time buffers are advisable, as delays of several months compared with the original plan occur frequently in practice.
Big bang or phased migration – which strategy is better?
With a big-bang migration, the switch to the new system happens completely on a single cutover date; this is faster and avoids duplicate data maintenance, but requires a thoroughly rehearsed cutover weekend and carries a higher risk if something goes wrong. A phased migration transfers modules or sites one after the other, thereby reducing the individual risk, but prolongs the transition period with both systems running in parallel. Which route fits depends on company size, number of sites and risk tolerance – with many sites, the phased approach dominates in practice. Regardless of the strategy, a documented fallback plan and several test migrations are critical to success.
What happens to historical data from the legacy system?
In practice there are three routes: full migration of all legacy data into the new system (often expensive and rarely necessary), selective transfer of individual balances and documents as the common standard, or permanent archiving of the historical data outside the new ERP. Tax-relevant records in Germany are subject to statutory retention periods – ten years for annual financial statements and inventories, eight years for accounting documents since 2025 – which continue to run regardless of the system change. According to the GoBD, after a system change it is generally sufficient to keep the machine-readable tax data available only on a data carrier from the sixth year after the switch, instead of operating the entire legacy system for the full retention period – provided that all data subject to retention requirements was transferred completely in both quantity and quality. It is therefore advisable to deliberately limit the migration scope and to archive legacy data that is not needed in an audit-proof manner rather than migrating it.
What does an ERP migration cost and what share is attributable to the data?
Total costs depend heavily on company size, licensing model and depth of customisation; as a rough guide, six-figure ranges circulate for mid-market projects, with many companies gauging the order of magnitude at a low single-digit percentage of annual revenue. The data migration itself is frequently underestimated and, depending on data volume and legacy system landscape, can account for a substantial share of the project budget. On top of this come licences, implementation services, interfaces and testing, plus training and change management, which is often budgeted at a double-digit percentage share. Early data cleansing noticeably reduces the later migration effort, which is why investing in data quality generally pays off.
Why do ERP migrations fail so often and how can this be avoided?
Industry studies such as the annual analyses by Panorama Consulting regularly report that a large share of ERP projects miss their targets and that budget and schedule overruns occur disproportionately often. The main causes are considered to be organisational factors rather than technical problems: poor data quality, uncontrolled scope growth (scope creep), weak test strategies, understaffed project teams and a lack of change management. Countermeasures include early and repeated test migrations, consistent cleansing of master data before the switch, and a clearly limited project scope. Equally important are timely user training and active support for the organisational change, as user acceptance often determines success more than the purely technical data transfer.
By when do SAP ECC users have to migrate to SAP S/4HANA?
SAP has set mainstream maintenance for SAP ERP 6.0 with Enhancement Packages 6 to 8 to end on 31 December 2027; after that, there will be no more regular security and functional updates under the standard terms. Older enhancement package levels (EHP 0 to 5) already expired at the end of 2025 with no extension option, while for EHP 6 to 8 extended maintenance is available until the end of 2030 for an additional fee. Since a complete transition from ECC to SAP S/4HANA often takes 18 to 36 months, an early project start is recommended, especially as a substantial share of existing customers had not yet completed the move by the stated deadline. In terms of approach, depending on the starting position, the options are a greenfield rebuild, a brownfield system conversion or a selective approach.