SAP S/4HANA is SAP’s current ERP system: the software that runs a company’s finance, purchasing, sales, manufacturing and supply chain. It replaced SAP’s older ERP, often called ECC, and it is built to run only on SAP’s in-memory database, SAP HANA. This guide explains what S/4HANA is, how it differs from ECC, the ways you can run it and what a move to S/4HANA involves.
In one sentence: SAP S/4HANA is SAP’s modern ERP suite, rebuilt on the SAP HANA database with a simpler data model, real-time analytics and the SAP Fiori user experience.
What the name means
The name breaks down simply. “S” stands for simple, “4” for the fourth generation of SAP’s core business software (after R/1, R/2 and R/3), and “HANA” for the database it runs on. SAP released the first part, SAP S/4HANA Finance, in 2015 and the full suite later the same year.
What S/4HANA does
Like every ERP, S/4HANA connects the core processes of a business in one system with one set of data. Typical end-to-end processes include:
- Order to cash: sales order, delivery, invoice and customer payment.
- Procure to pay: purchase requisition, purchase order, goods receipt, supplier invoice and payment.
- Plan to produce: demand planning, production orders and inventory.
- Record to report: postings, closing and financial statements.
- Hire to retire: often handled with SAP SuccessFactors alongside S/4HANA.
How S/4HANA differs from ECC
| SAP ECC | SAP S/4HANA | |
|---|---|---|
| Database | Several databases (Oracle, SQL Server, DB2, HANA and others) | SAP HANA only |
| Data model | Many aggregate and index tables | Simplified; totals calculated on the fly |
| Finance | Separate ledgers for finance and controlling | One Universal Journal (table ACDOCA) |
| Customers and vendors | Separate master data | One Business Partner object |
| User experience | Mainly SAP GUI transactions | SAP Fiori apps in the browser, plus SAP GUI where needed |
| Analytics | Mostly in a separate data warehouse | Embedded, real-time analytics on live data |
| Support | Mainstream maintenance ends 31 December 2027 | Supported for many years ahead |
The biggest practical changes for users are the Fiori screens, the Business Partner and the Universal Journal. For IT teams, the big changes are HANA, a cleaner data model and the “clean core” approach to customization.
The ways to run S/4HANA
S/4HANA comes in three main deployment options. SAP now also uses the umbrella name SAP Cloud ERP for its cloud editions.
| Option | What it is | Good fit for |
|---|---|---|
| S/4HANA Cloud Public Edition | Software as a service, shared (multi-tenant), updated by SAP on a fixed schedule, with standard processes and strict clean-core rules | Companies happy to adopt standard processes, new implementations, subsidiaries |
| S/4HANA Cloud Private Edition | A dedicated system run by SAP in the cloud, usually bought through RISE with SAP; same software as on-premise | Large or complex companies moving from ECC that need flexibility |
| S/4HANA on-premise | Installed and run by the customer or a partner on infrastructure they control | Companies that need full control of their landscape |
Release names differ too. The public edition uses year-and-month numbers (for example 2602 for February 2026) and gets new releases twice a year. On-premise and private edition releases use the year, such as 2023 and 2025, with a new release every two years since 2023 and feature packs in between.
Why companies are moving now
SAP’s mainstream maintenance for ECC ends at the end of 2027, with paid extended maintenance available to the end of 2030. That deadline, plus the fact that SAP’s newest innovation, including its AI assistant Joule and AI agents, is focused on S/4HANA and the cloud, is why so many companies are running S/4HANA projects right now.
How companies move to S/4HANA
There are three common approaches:
- Brownfield (system conversion): convert the existing ECC system to S/4HANA, keeping history and most configuration. Faster, but you also bring old habits and custom code with you.
- Greenfield (new implementation): start fresh with S/4HANA and standard processes, then migrate selected data. More change, but a cleaner result.
- Selective data transition: a mix of both, moving chosen company codes, processes or history into a new S/4HANA system, usually with specialist tools.
Whatever the approach, most projects include a readiness check, custom code analysis, data cleansing, testing, training and, importantly, a redesign of roles and authorizations.
Clean core: customizing the modern way
In ECC, companies often modified SAP’s own code. With S/4HANA, SAP recommends a clean core: keep the ERP close to standard and build extensions through released APIs, in-app extensibility tools, or side-by-side on SAP Business Technology Platform (BTP). A clean core makes upgrades faster and cheaper, and it is required in the public edition.
What changes for SAP security
S/4HANA changes how access works, so security teams have real work to do in any move:
- Fiori apps need launchpad content (catalogs, spaces and pages) as well as back-end authorizations.
- Many old transactions are replaced or removed, so roles must be remapped.
- Authorization objects and default values change, which is handled with transactions SU24 and SU25.
- Segregation of duties rules need updating for new apps and the Business Partner.
Teams that plan the role redesign early avoid a flood of access errors at go-live.
Frequently asked questions
Is S/4HANA the same as SAP HANA?
No. SAP HANA is the database. S/4HANA is the ERP application that runs on it.
Is S/4HANA only in the cloud?
No. It can run on-premise, in a private cloud (often through RISE with SAP) or as the public cloud edition.
Can I still use SAP GUI in S/4HANA?
Yes, in the on-premise and private editions many classic transactions still work, although SAP Fiori is the main user experience and some functions are only available as Fiori apps.
How long does a move to S/4HANA take?
It depends on the company’s size and approach. Small, standard implementations can take months, while large global conversions often take one to three years.
The bottom line
SAP S/4HANA is the present and future of SAP ERP. It runs on SAP HANA, simplifies the data model, brings real-time analytics and the Fiori experience, and is where SAP’s AI innovation lands first. With ECC support ending, understanding S/4HANA, and how to secure it, is one of the most valuable SAP skills you can build.
