SAP's Shift in Terminology: From Custom Development to Extensibility
SAP terminology has shifted meaningfully from ECC to S/4HANA.
In ECC, most consultants spoke in terms of configuration, custom development, enhancements, and modifications. In S/4HANA, especially under Clean Core, SAP uses a different organizing idea: extensibility.
This is not just a vocabulary change. It reflects a change in SAP's philosophy: keep the core stable, upgrade-safe, and extended through supported mechanisms.
SAP ECC Terminology (SAP ERP / ECC 6.0)
This is the terminology most SAP consultants use.
| Term | Definition |
|---|---|
| Configuration (Customizing) | Adapting SAP standard behavior by maintaining configuration data (IMG/SPRO) without writing code or changing SAP standard objects. |
| Custom Development | Customer-developed ABAP repository objects that implement business requirements not covered by standard SAP functionality. |
| Enhancement | Adding customer-specific behavior at SAP-defined enhancement points without modifying SAP standard objects. Examples include BAdIs, customer exits, user exits, Business Transaction Events (BTEs), and enhancement spots. |
| Modification | Directly changing SAP-delivered repository objects such as programs, classes, function modules, or dictionary objects. |
ECC Relationship
Customer-specific adaptation
|
+-- Configuration (Customizing)
|
+-- Custom Development
| +-- Z programs
| +-- Z reports
| +-- Z classes
| +-- Z tables
| +-- Interfaces
| +-- Forms
| +-- Enhancements
| +-- BAdIs
| +-- Customer Exits
| +-- User Exits
| +-- BTEs
|
+-- Modification
SAP S/4HANA Clean Core Terminology
SAP deliberately changed the vocabulary to emphasize upgrade-safe extensions.
Notice that Custom Development disappears as the primary organizing concept. SAP instead talks about Extensibility.
| Term | Definition |
|---|---|
| Configuration | Adapting SAP standard functionality through business configuration without changing SAP source code. |
| Key User Extensibility | Business-user extensions created using in-app tools, such as custom fields, UI adaptations, custom business logic, and forms. |
| Developer Extensibility | Extensions implemented by developers using released APIs, extension points, and ABAP Cloud. |
| Side-by-Side Extensibility | Extensions implemented outside the SAP S/4HANA system, typically on SAP Business Technology Platform, using APIs and events. |
| Modification | Direct changes to SAP-delivered objects. Strongly discouraged under the Clean Core strategy. |
S/4HANA Relationship
Customer-specific adaptation
|
+-- Configuration
|
+-- Extensibility
| +-- Key User Extensibility
| +-- Developer Extensibility
| +-- Side-by-Side Extensibility
|
+-- Modification
Mapping Between ECC and S/4HANA
| ECC terminology | S/4HANA terminology | Relationship |
|---|---|---|
| Configuration (Customizing) | Configuration | Equivalent |
| Custom Development | Developer Extensibility | Similar intent, but Developer Extensibility is narrower because it requires SAP-supported extension mechanisms and released APIs. |
| Enhancements | Developer Extensibility | BAdIs and other supported enhancement implementations fit naturally here. |
| Z Programs | Developer Extensibility, only if compliant with ABAP Cloud and released APIs. Otherwise, legacy custom development. | Not a one-to-one mapping. |
| Customer Exits | Developer Extensibility (legacy) | Many remain supported for compatibility but are legacy techniques. |
| Modifications | Modifications | Equivalent |
The Biggest Conceptual Shift
The change is not just terminology. It reflects a change in SAP's philosophy:
- ECC asks: "How do I customize SAP?"
- S/4HANA asks: "How do I extend SAP while keeping a clean core?"
That is why "custom development" is no longer the umbrella term in SAP's modern documentation. The umbrella term is Extensibility, with Key User Extensibility, Developer Extensibility, and Side-by-Side Extensibility as its primary categories.
SAP References
Core Extensibility Documentation
- SAP Help Portal: Developer Extensibility (SAP S/4HANA Cloud Public Edition)
- SAP Help Portal: Understanding Available Technology
- SAP Help Portal: Enabling Standard Behavior Extensions
- SAP Help Portal: About Namespaces
Clean Core
Key User Extensibility
ABAP Cloud and Classic ABAP
The ABAP Resource Center includes whitepapers and videos such as:
- Extend SAP S/4HANA in the cloud and on premise with ABAP-based extensions
- Classic ABAP to ABAP Cloud
- ABAP Cloud for Classic ABAP Developers
These are some of the most useful SAP references for understanding the transition from the ECC-era terminology "Custom Development" to the S/4HANA Clean Core terminology "Developer Extensibility", "Key User Extensibility", and "Side-by-Side Extensibility".