SAP S/4HANA Extensibility Options For Clean Core J...

jeetendrakapase · ‎2023 May 01

Experts, before getting into the topic, let's understand the motivation and purpose of the new modern extensibility options defined by the SAP for SAP S/4HANA Public, On-premise, and PCE editions.

Motivation

A cloud-first approach is becoming the new normal powered by software-as-a-service (SaaS) applications with AI/ML, digital assistants, automating routine tasks, better user experience, flexible and agile operating model. SAP is bringing innovation into the core ERP business processes with frequent product release updates. SAP also provides freedom to go beyond standard ABAP language with a BTP side-by-side extensibility approach using BTP ABAP Cloud, Java, node.js, BYOL, etc. to build full-stack applications which will run in parallel with ERP which is challenging with the classic extension options. The extensibility option is a key capability of an ERP application that enables customers to customize their business processes with a competitive advantage in the industry and allows partners to enrich ERP with tailor-made solutions. The importance of extensibility has been confirmed by the legacy ERP flagship product SAP ECC and will remain valid for the current and future cloud ERP transformation.

SAP S/4HANA is a front-runner product providing intelligent ERP in the cloud and on-premise. The goal is to shift from the classic ABAP extensibility model to an SAP S/4HANA modern extensibility model that allows customers to consume SAP innovations, building future-proof extensions that are ready for the cloud ERP. For all, it is important to understand and know how SAP is shifting away from a monolithic architecture (SAP ECC era) to a microservices architecture that is modular, flexible, continuous deployment, and agile (SAP S/4HANA era with BTP).

There is chaos in the developer's community, how do we connect the dots for customers that are on traditional ABAP so they can take advantage of modern innovations? What is a new extension model? What is Embedded Steampunk, BTP ABAP environment? SAP CAP (Java, node.js) or RAP? What is Side-by-side BTP Extension? How it is different from standard ABAP? Where can we use SAP Build Apps with ERP? And more questions.

*** Blog Last Updated on 04/22/2025 ***

Current customer situation

Our current ABAP customizations deliver but at a cost. Extensive modifications have led to complexity and inefficiency. While classic extensibility is powerful, it struggles to maintain a high-performing system with ongoing needs. This translates to high IT costs and hinders innovation. Our goal is to transform into an Intelligent Enterprise with a modern, digital ERP. This will reduce costs, boost agility, and unlock value from our data.

Challenges with the classic extensibility model

Slower and More Difficult to Innovate (69% of companies say technical debt limits their capacity to innovate)
- Unable to meet business requirements promptly (small or new project) loses competitive advantage and slower innovation.
- Unable to serve business stakeholders. If they are unhappy so does business.
- Staffing and Managing IT for long-term upgrade projects.
High TCO for system maintenance and software upgrades( Companies with high technical debt become 1.6X less productive).
- Extensive planning and testing. Make sure the upgrade does not break the system.
- Classic extensibility adds complexity to the SAP Core and prevents from adoption of agile practices and standardized business processes.
- Redundant data and unused custom code living within the core ERP system. Duplicate IT spend.
- Example: You have used an SAP object that is not whitelisted by SAP in your extension. After an upgrade, the used SAP object has been changed or deleted. Now you will have to adjust the extension thus upgrade is delayed and the speed of innovation is decreased.
- Software changes lead to high adoption efforts.SAP Standard code and Customization are not separated, there is no interface.

What are the extensions?

Software engineering principle for enhancements without impairing existing system functions.
It can be the addition of new functionality or modification of existing functionality.
Measure the ability to extend and the effort required to implement an extension.

Why does SAP S/4HANA ERP need extensibility?

Extend business process for optimization, innovation, or automation
Extend the UX of existing processes and provide controlled access for external user groups
Extend data insights & analytics by combining data in one central place
Extend the ecosystem with side-by-side Software as a Service (SaaS) apps

What and why about the clean core concept?

Let's understand the meaning behind the Clean + Core .

Clean...  up-to-date, transparent, unmodified, consistent, efficient, and cloud compliant.

Core...  the main aspects of an ERP system are extensibility, processes, data, integration, and operation.

The clean core is an extension methodology concept with the basic goal i. e.  Extensions should not break an upgrade and upgrades should not break an extension. Follow the rules:

Fit-to-Standard: Leverage SAP standard processes when possible.
Apply a zero-modification policy from the project’s first day.
Leverage the full potential of new extension options (In-App, Developer, or Side-by-Side ) which fit your needs best.Use whitelisted and released APIs .
Eliminate enhancements that are redundant to standard code and functionality, as well as “clones” of standard code.
Think and act like moving SAP S/4HANA on-premise to SAP S/4HANA Cloud by using the capabilities of SAP BTP Extension & Integration Suites for application development and integration.

Some principles when building extensions to keep the core clean.

Clean core pillars:

Extensibility: Keep the extensions clean.
Data: Keep the data clean.
Integrations: Keep the landscape reliable.
Processes: Keep the processes close to standard and flexible for the business.
Operations: Effective, efficient for the operations and automate if possible.

Clean Core for Developers: Prioritize Standard Functionality Before extending SAP S/4HANA, explore all other options to fulfill your needs.

Here's a developer-friendly approach to a Clean Core strategy:

Exhaust Standard Solutions:
- Prioritize using pre-built, Clean Core-compliant partner solutions.
- Leverage the latest SAP S/4HANA functionalities like SAP Fiori and built-in features.
- Utilize SAP Signavio tools to identify relevant standard SAP solutions and avoid unnecessary extensions.
Extend Only When Necessary:
- Implement custom extensions only if essential.
- Ensure these extensions are upgrade-stable and well-documented for future maintenance.
- Focus on actively used extensions and eliminate any unused or redundant ones.
Maintain Clean Code:
- Adhere to strict code quality standards and best practices.
- Avoid replicating existing SAP functionalities within your extensions.
- Streamline processes by decommissioning inefficient ones.
Embrace Innovation:
- Utilize the latest SAP S/4HANA features like SAP Fiori, Machine Learning, and Situation Handling to address your needs without extensions.
- Take advantage of new business processes that are available only through SAP Fiori.

How to

plan and adopt a clean core strategy for an SAP S/4HANA ERP transformation project?

Greenfield project: Start with the stay clean strategy to bring the system the system closer to standard processes, and keep the system up-to-date, including modern extensibility and integration options and data governance. Follow the clean core principles from the beginning.

Brownfield project: Start with the get and keep clean strateg y to bring system the system closer to standard processes, including clean core principles for all new ERP deployments.

Develop a roadmap with iterative steps for existing systems to achieve a clean core. Recognize clean core is a continuous journey, not a one-time fix.

Understood! Tell me the benefits of it:

Reduce TCO (Time, Effort & Cost)
1. Flexibility with faster deployment and Ready for a smooth upgrade.
2. Reduce test efforts for business users and Adoption efforts for developers.
3. IT service providers can offer upgrade projects at a fixed price.
4. No costly maintenance for unused artifacts and data.
Innovation at Market Speed
1. Captivate innovation delivered by SAP.
2. React fast to changing business requirements.
Data to value.
1. Consistent data allows for reliable forecasting and predictions for confident decisions.
Become cloud-ready and Competitive at any point in time.
1. Moving SAP S/4HANA on-Premise to SAP S/4HANA Cloud.

Learn more, Get your organization in shape: Keep a Clean Core with SAP Business Technology Platform.

Now you have clarity clean core concept and benefits. Let's get into the main topic.

What is the new extensibility model?

This new SAP S/4HANA Cloud extensibility model, first introduced in SAP S/4HANA Cloud public edition, is now available and recommended in all SAP S/4HANA editions, to achieve the following:

Smoother upgrades.
Little to no testing efforts.
Simplified adoption and LOBs drive innovation timelines.
Standardized and optimized business processes.
Pave the way to the cloud.

Let's understand the various new options/tools available to create stable extensions in the SAP S/4HANA ERP system by following the clean core principle, even when the classic extensibility model is still available for the on-premise, private editions and recommendations are NOT to adopt it.

SAP S/4HANA Extensibility Model Options

The new extensibility model in SAP S/4HANA can be divided into three parts:

Key User Extensibility in the SAP S/4HANA Core Stack
Developer Extensibility in the SAP S/4HANA Core Stack
Side-By-Side Extensibility on the SAP Business Technology Platform

1. Key User (In-app) Extensibility

SAP Fiori extensibility apps(tools) help you customize applications and their UIs, reports, email templates, and form templates using a low-code/no-code(LCNC) paradigm.. Using extensibility apps, you can create extensions without the need for extensive coding skills. Some development skills are recommended for developing custom business objects and adding business logic using the cloud ABAP web editor. Scenario

Extensibility tools empower key business users to make non-disruptive customizations to the system on their own, minimizing risk and allowing them to focus on adding business value and no deep technical knowledge required.

Use-cases

UI adoption for screen layouts such as moving/hiding fields and field groups, changing labels, etc, custom forms, and templates
Custom CDS views and analytical apps.
Custom business objects with minimal coding effort.
Data source extension: Extend SAP CDS Views and OData Services with SAP fields that are available in CDS views in "lower layers'' of the Virtual Data Model
Custom fields to standard business objects. The custom field is then available in the entire application stack (from the UI to the database tables or for developer extensibility).
Custom business logic using Cloud BADIs
Custom Reusable Elements - Custom Code List and Custom Libraries.
Add custom fields to a process group (e.g., from sales quotation and sales order to delivery and invoice) to provide consistent end-to-end extensibility.
Copy and adapt print and email form templates.
The adaptations made by a key user are registered in transport requests for propagation into QA and PRD systems.

Benefits

Fully managed and tightly integrated into the SAP S/4HANA stack.
No or only very basic development skills required

User Personas Business expert, functional consultant, SME, or even IT resource Tools Extensibility Fiori Apps, Cloud ABAP web editor Clean Core Index High Learn More

The main argument for using key user extensibility is that simple extensions can be realized quicker than with developer extensibility because of the communication overhead between the business expert (responsible for the specification of the extension, and later for testing and approval) and the developer (responsible for development and developer test) is avoided.

Find other Key User Extensibility apps:

Go to the SAP Fiori apps reference library
Search for the title of the app you want to configure
Choose your product (S/HANA Cloud or S/4HANA)
Change to the tab Implementation

Key user Extensibility Pattern Architecture:

Key User Extensibility Tools

2. Developer Extensibility

This option bridges the gap between the key user and side-by-side extensibility options.It enables you to develop custom ABAP code and partner extensions in an upgrade-stable, cloud-ready programming model using the ABAP Cloud development model. Scenario

Custom ABAP development projects that need tight coupling to SAP S/4HANA data, transactions, or apps that require full access to development capabilities like debugging, refactoring support, version control, etc.

Use-cases

ABAP-based custom apps and extensions that are developed with a new cloud-ready ABAP RAP model on released APIs.
Custom applications with SQL access to SAP S/4HANA data cannot be realized by side-by-side or data replication.
Custom extensions running in the same logical unit of work (LUW) as SAP applications
Custom remote APIs or services for side-by-side SAP BTP apps
SAPUI5 Adaptation Project to extend the SAP Fiori application

Benefits

Full access to development capabilities inside the S/4HANA stack.
No remote access or data replication.
Use and extend released SAP S/4HANA objects.

User Personas ABAP developer, Fiori (UI5) developer Tools Eclipse-based IDE (ABAP Development Tools)

SAP Business Application Studio (SAPUI5 Adaptation Project), VS Code Clean Core Index High Learn More

Eclipse-based IDE (ABAP Development Tools) with a debugger, troubleshooting, and testing tool support
A cloud-optimized subset of ABAP language i.e. ABAP Cloud syntax .
ABAP RESTful Application Programming model (RAP) to build upgrade-safe extensions inside your core ERP system.
Only use released APIs and the stricter syntax check of ABAP Cloud. (Note that to fully utilize this you need to be on a recent version of S/4HANA >= 2022 though it's still possible to follow this system with older releases.)

In contrast to side-by-side extensions, on-stack developer, and key user extensions are developed and run on the same software stack as the underlying SAP S/4HANA system. This allows extensions to direct access SAP S/4HANA logic and data via SAP extension points(BAdis), local public CDS views, SAP-released APIs, or SQL queries.

Developer Extensibility Pattern Architecture

ABAP cloud development in the private cloud and on-premise editions of SAP S/4HANA

Switch from classic ABAP extensibility (standard ABAP) to ABAP for cloud development for a development object or package
Inspect the “Release state” for used APIs and objects
The ABAP cloud development model ensures that only released local APIs of the underlying ABAP Platform can be used.

ABAP for Cloud Development

Developer Adaptation Project

SAPUI5 Adaptation Project allows developers (typically a user from the IT department) to extend the SAP Fiori application in SAP Business Application Studio. Developer adaptations are modification-free, upgrade-safe, and can extend standard apps without needing pre-defined extension points.SAPUI5 Adaptation Project lets you create an app variant for an existing SAP Fiori elements-based application or freestyle application, on the SAP S/4HANA on-premise ABAP system or the Cloud Foundry environment and provides extension capabilities for UI5 controls.

UI adaption requirements can be covered by either key user or developer project adaptation, it is up to you to decide. Using key user adaptation of course has the advantage that it is a no-code environment, easy to use for business experts and it comes without the need to set up an IT project in the BAS. Hence most customers choose to use key user adaptation as much as possible. Learn more about when to use adaptation projects and use cases.

Adaptation projects are currently only supported on the S/4 HANA on-premise ABAP system or the Cloud Foundry environment, for the S/4HANA cloud it may be supported in the future, refer to the product roadmap for more details. SAP S/4HANA cloud extensibility explorer.

3. Side-by-side Extensibility

Extensions running on the separated (side-by-side) SAP Business Technology Platform (SAP BTP) for all other loosely coupled extension scenarios integrating with the extended SAP S/4HANA system. This model is the preferred option for developing loosely coupled but seamlessly integrated extensions to SAP S/4HANA data, transactions, or apps. Scenario

Loosely-coupled extensions, process automation, and applications, such as partner SaaS solutions or custom applications targeting a different end-user group.

Use-cases

Proxy applications for a separate target group (no ERP users)
Convenience application workload that shall run separated from ERP
A custom application that will run in parallel with ERP reducing the load on the operational system.
Custom applications needing proximity to intelligent SAP BTP services like machine learning, AI, etc.
Substitute apps integrating with several ERP and cloud services
Partners want to provide a SaaS solution and therefore need to operate their service independently of the SAP S/4HANA system.
ABAP and non-ABAP (Java, Node.js, etc.) developments
Extend UI application using a no-code application like SAP Build Apps
ERP Workflow and business process automation
Pre/Post processing applications for S/4HANA system.
Analytical applications.

Benefit

Decoupled extensions and developments that are independent of SAP S/4HANA operation and run independently.
Independent lifecycle management.
Choose to use ABAP or non-ABAP (Java, Node.js) development.

User Personas ABAP developer, BTP full-stack developer, Citizen developer Tools

PRO-CODE:

- Eclipse-based IDE (ABAP Development Tools)

- SAP Business Application Studio / SAP Build Code

- VS Code

LOW-CODE:

-SAP Build Apps

-SAP Build Process Automation

-SAP Build Work Zone

Clean Core Index Medium to High Learn More

Develop custom code side-by-side extension and SaaS solutions using ABAP RESTful Application Programming Model (RAP) and SAP Cloud Application Programming Model using Java, or Node.js. Use no-code/low-code applications like SAP Build Apps, Process Automation, and Build Workzone to build custom applications, process automation, and workflow management. One main difference compared to the on-stack extensibility model is that accessing business objects of SAP S/4HANA Cloud is only possible using remote APIs which are published in the SAP API Hub.

Side-by-side Extensibility Pattern Architecture

3.1 PRO-CODE

ABAP RESTful Application Programming Model (RAP)

New ABAP programming model for efficiently building cloud-ready enterprise apps and upgrade-stable extensions on SAP BTP ABAP environment, SAP S/4HANA Cloud, SAP S/4HANA Cloud ABAP environment, and SAP S/4HANA 1909 and higher.

RAP is a powerful framework consisting of a set of concepts, tools, and languages.
A strategic long-term solution for the ABAP developments.
Help developers to build innovative, cloud-ready, enterprise applications of different domains, such as transactional and analytical applications.
RAP offers a standardized development flow based on Core Data Services (CDS), the ABAP language, and business services in the modern, Eclipse-based ABAP Development Tools (ADT) .
RAP is available on
- SAP BTP ABAP Environment (Steampunk), provides the ABAP platform as a service (PaaS) on SAP BTP. ABAP-minded customers and partners can reuse their ABAP skillset to build new cloud solutions, or to transform already existing on-premise ABAP assets to the cloud.
- SAP S/4HANA ABAP Environment (Embedded Steampunk)

High-level RAP Programming Model

SAP Cloud Application Programming Model(CAP)

An open and opinionated framework of languages, libraries, and tools for building enterprise-grade services and applications. The CAP framework features a mix of broadly adopted open-source and SAP technologies

CDS is the backbone of the SAP Cloud Application Programming Model (CAP) to build data models, defining the UI layer with those definitions (annotations) and service definitions on a conceptual level.
CAP-based projects benefit from a primary focus on the domain rather than delving into overly technical disciplines.
SAP programming model is compatible with any development environment, but recommend using the SAP Business Application Studio.

High-level CAP Programming Model

SAP CAP Vs RAP model, which one to choose? The choice of the programming language for your extension – ABAP, Java, or JavaScript is decisive.

Common	ABAP RAP Model	SAP CAP Model
• RESTful OData services • Core data services (CDS) • Built-in extensibility capabilities, enabling users to extend both SAP Cloud Application Programming Model and ABAP RESTful application programming model in a similar way as with the key user (in-app) extensibility of SAP S/4HANA	• ABAP programming language • Git-enabled lifecycle management • Offers a service consumption model for easy remote OData service calls • Enables the possibility to reuse selected custom code in the cloud with SAP BTP, and ABAP environment, while rebuilding the UI and backend access • Eclipse IDE	• Supports Java or JavaScript (node.js) • Enables applications originally written as a single-tenant applications to be turned into multitenant ones through configuration • Leverages event-based communication using the SAP Event Mesh capability • Wraps the REST service calls to the underlying back-end system to Java or JavaScript functions using SAP Cloud SDK

3.2 LOW-CODE

SAP Build Apps

Evolution of SAP AppGyver is a professional application development solution designed for anyone to quickly create apps without code regardless of role or skill level.

Build Full-Stack Enterprise-Apps in Minutes - Absolutely Zero Coding Required
Drag-and-drop the user interface and Create any logic without code.
With SAP Build Apps everyone can become a full-stack cloud developer.
Easily add your own data integrations or get started with some of ours.
Users can design both mobile and web applications with a pixel-perfect design using the drag-and-drop functionality and a rich component library.

Note: SAP Build Apps is still evolving and due to limitations on the availability of different hyper scalers, other low code and pro code solutions become equally important.

SAP Build Process Automation

A citizen developer solution to automate workflow processes and tasks without writing code.

Users can create forms, manage decision logic, and build, adapt, and organize process flows with drag-and-drop simplicity.
Automate repetitive manual tasks - such as copy-and-paste operations, data extraction, data entry, and data creation - using no-code and low-code capabilities or the built-in automation recorder.
Built-in AI capabilities enable intelligent document processing –like extracting data from structured or unstructured documents to transfer it to your enterprise systems for processing - without needing data scientist support.
Simplifies process and task automation so business users can unleash their process expertise without writing code.
Adapt, improve, and innovate business processes with no-code workflow management and robotic process automation capabilities.

SAP Build Work Zone

Enables non-technical professionals to navigate complex enterprise technology systems, landscapes, and tools. With drag-and-drop and customization tools to create portals, intranets, and workspaces, you can bring together all types of content, UI tools, IT systems, content repositories, applications, and channels.

Users can create beautiful, custom business sites for themselves, colleagues, suppliers, customers, partners, etc., without writing any code.
Business sites created with SAP Build Work Zone provide central access to relevant applications, processes, and information.
Maximize productivity by enabling guided experiences and knowledge sharing.

The three extensibility options are not isolated from each other. In many scenarios they are combined, for example, developing a side-by-side application in conjunction with a thin on-stack extensibility layer that offers more suitable remote APIs to access the SAP S/4HANA Cloud functionality.

4. Classic Extensibility (Not available in SAP S/4HANA public edition)

This is the traditional way of the SAP ECC or S/4HANA on-prem enhancement for RICEFW ABAP custom object development like user-exits, customer-exits, classic BAdis, implicit/explicit enhancements, BTE, module-pool, etc using transaction code SE38, SE80, SE11 (SAP GUI, Eclipse ADT). Scenario Requirements that are critical for lifecycle management or business operations and NOT possible using 3 modern extensibility options(Key user, developer, or side-by-side) Use-cases

Non-released BAdis, classic user exits business-critical logic.
Lastly, anything that is not possible to accomplish using modern extensibility options for must-have type business application requirements.

Benefit

Extremely powerful and flexible.
No restriction on the extension model.

User Personas ABAP developer Tools SAP GUI - Tcodes

Eclipse-based IDE (ABAP Development Tools) Clean Core Index Low Learn more

Help Portal - Classic Extensibility

Basically using non-released objects from S/4HANA and an ABAP standard version (non-restricted). No restriction on the extension, it even allows you to modify the standard SAP code itself. Hence, upgrade effort increases and agility/innovation speed decreases.

Classic Extensibility Pattern Architecture

In SAP S/4HANA On-Premise –The classical extensibility option is available but not recommended .

Available extensibility options for SAP S/4HANA editions

Key user, developer, and side-by-side extensibility are available for public and on-premise editions while the classic extensibility model is available only for an on-premise edition.

3-tier extensibility model for SAP S/4HANA On-premise and PCE editions

Refer official guide Chapter 5: EXTENDING A NEW SAP S/4HANA CLOUD PRIVATE EDITION OR SAP S/4HANA ON-PREMISE SYSTEM

3-tier extensibility model

How to

How to handle Classic Custom Code migration?

This is the most important step for customers who have been using classic extensibility with the standard ABAP. For them, it's a two-fold process:

Analyze the classic ABAP custom code with the Custom Code Migration App to estimate the impact. Custom Code Analysis for SAP S/4HANA with SAP Fiori App Custom Code Migration
Detect and Retire unused classic ABAP custom code. In the analysis, it is found that roughly 60% (sometimes even more) of the code is not used productively in a typical ERP system. Removing obsolete code significantly reduces the effort for custom code adaptation. At the same time, this is certainly a first step toward a clean digital core.

Learn more: ABAP Testing and Analysis

Clean Core Dashboard:

The Clean Core Dashboard is a tool for monitoring the clean core compliance of your productive SAP S/4HANA Cloud Private Edition systems. Launched in August 2023 through the SAP for Me portal (Systems & Provisioning), it provides insights into how closely your system adheres to clean core principles. This dashboard is continually evolving, with new KPIs planned for future updates.

Important Note: Access to the Clean Core Dashboard is restricted to:

Productive Systems
SAP S/4HANA Systems that are RISE Systems managed by SAP Enterprise Cloud Services (ECS)

ABAP Cloud Use Cases - Overview and Recommendations

Refer official guide: ABAP Cloud - Technical Use Cases and Recommended Technologies

Classic RICEFW Vs Modern Extensibility With BTP

Classic RICEFW	Modern Technology/Extensibility
Reports	•SAP Fiori Analytical Apps •SAP Custom Fiori Apps •Decoupled from the core on BTP using released APIs, Integration Suite •SAP Analytics Cloud
Interfaces	• Extension of standard OData services or creation of new ones based on custom core data services (CDS) views with SAP S/4HANA key user (in-app) extensibility • SAP Integration Suite • SAP Application Interface Framework tool (part of SAP S/4HANA) • Event brokering using SAP Event Mesh
Enhancements	•Custom business logic with SAP S/4HANA in-app extensibility and Developer Extensibility •BTP Cloud Foundry Runtime, Event Mesh - Business Events / Workflow
Custom Tables	•Custom business objects with generated UI with SAP S/4HANA in-app extensibility and Embedded ABAP
Modifications	•Key user (in-app) extensibility in SAP S/4HANA covers a wide range of business requirements for UI adaptation and business logic. •On-stack Developer Extensibility •Developer Adaptation Project
Conversions	• SAP S/4HANA migration cockpit to load data
Forms	• SAP S/4HANA output management: custom forms with Adobe LiveCycle Designer with OData as a data source • Forms as Service on BTP
Workflows	•SAP S/4HANA flexible workflow •SAP Build Apps.
User Interface	•SAP Mobile Services, SAP Build Work zone. •SAP Fiori, UI5
Data-Marts	• Embedded BW with CDS views, Table Functions, and AMDP or SAP Datasphere, BW/4HANA, HANA cloud
Machine Learning	•Embedded ML based on SAP Analytics cloud. •Side-by-Side ML is used for Complex ML scenarios based on the SAP BTP (Data Intelligence, SAP HANA PAL, AI Business Services, AI Core). •Intelligent Scenario Lifecycle Management (ISLM) scenarios in SAP S/4HANA

Decision Tree for Extensilibty Options

Decision Matrix for Extensibility Options

Refer official guide Chapter 3: WHEN TO USE WHICH CLOUD EXTENSIBILITY OPTION

Requirements	Key-User	Developer	Classic	Side-by-side
End-Users and User Experience (UX):
External users (B2B / B2C, Fiori, non-Fiori) for service orders, master data self-services etc.				X
Multi-Channel (mobile) and Mobile native capabilities				X
Allow collaboration with business partners and internal employees who don't have full access to the SAP system.				X
Involve employees (B2E) without access to the business solution				X
SaaS solution integrates SAP and third-party on-premise, cloud, and hybrid products				X
Adapt existing UIs based on the SAP Fiori UX	X
Modernize existing UIs or redesign them for a better user experience.				X
Open-source components and freestyle UI (non-SAPUI5/SAP Fiori)				X
Business Processes:
Extend standard functionalities with focus on SAP S/4HANA data.		X	*X
Develop separate applications with occasional data exchange with SAP S/4HANA.		X	*X	X
Extensions that store custom data in the same logical unit of work as the extended SAP S/4HANA app	X
Strong consistency with SAP transactions (e.g., updates in the same logical unit of work).	X	X	*X
Tightly coupled and highly complex extensions directly interwoven with SAP code.			*X
Non-released BAdis, classic user exits business-critical logic			*X
Is a hub scenario (i.e., integrates with SAP and Non-SAP solutions and services)				X
Application with unpredictable or largely varying usage and resource consumption (scalability and elasticity)				X
Data and Analytics:
Analytical Key User Use Cases	X
Analytical application consuming standard and custom data residing in SAP S/4HANA	X	X
Consolidate data from various sources (SAP and external systems) for analysis.				X
Emerging Technologies, e.g. AI,ML, also from other Hyperscalers				X
Features:
Agility and independence on the back-end lifecycle				X
Reactive (event-based) process extensions and custom workflows				X
Use of SAP and third-party cloud services				X
Application with unpredictable or largely varying usage and resource consumption (scalability and elasticity)				X
Non-ABAP, Other Skillset (Benefits from a broad spectrum of developers with different skill sets )				X
Can or should be decoupled (loosely coupled) from SAP S/4HANA core	X
Is a hub scenario (integrates with SAP and Non-SAP solutions and services)		X

*X - Not applicable for S/4HANA Public Cloud

The clean core is a journey to be agile, reliable, and more efficient. You can not just switch it on overnight. 😉

Questions?, Please use the blog comment feature or reach out to me on Linkedin.

FAQs:

1.If I create a custom Z table and CDS view, will I be adhering to the clean core principle?
Yes. Creating custom objects (like Z tables and CDS views) within ABAP Cloud is compliant with the clean core principle. The core goal of clean core is to avoid modifying standard ERP objects and to only extend released objects.

2.Are user exits, customer exits, implicit enhancements, and explicit enhancements considered clean core?
No. Instead of using these classic enhancement techniques, you should implement SAP-released BAdIs for extensions within the ABAP Cloud released version.

3.Is SAP S/4HANA Public Cloud, by default, a clean core system?
Yes. S/4HANA Public Cloud inherently follows the clean core principle. It does not offer classic extensibility options. Instead, it provides key-user extensibility and side-by-side extensibility.

4.How can I find SAP-released BAdIs and other released objects?
You can find them in the Cloudification repository: https://sap.github.io/abap-atc-cr-cv-s4hc/?objectTypes=BADI_DEF . Alternatively, log in to your Public Cloud ERP system's ADT repository and navigate to "Released Objects" to see a list of all released objects.

5.Should standalone custom applications be built using side-by-side extensibility rather than the clean core stack?
It depends on the use case. If the application utilizes on-stack data, you can define the logic within the core system and use Fiori for the UX. This avoids unnecessary calls. If the execution logic or transactions reside within S/4HANA, the extension should stay within S/4HANA. Side-by-side extensibility is more appropriate for scenarios like reporting, integration with external systems, updating few fields via external users, or retrieving data from multiple loosely coupled ERP systems.

Summary

SAP S/4HANA provides a new extensibility model that clearly separates standard and custom developments.
The classic extensibility option is not available for SAP S/4HANA public edition.
A clean core strategy is important for customers to consider while extending an ERP application and be ready to consume product updates and innovations.
Key-user extension is a great tool for business users without the need for IT support.
Side-by-Side is an extensibility model that provides freedom to choose ABAP, Java, Node.js, etc., and build a full-stack application that will run in parallel with core ERP processes.
An embedded ABAP environment offers values for both greenfield and brownfield projects.
Retire unused code, Custom code migration and developments with modern cloud ABAP is a go-forward strategy to become cloud competent, modularized, and agile for business needs.

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Credits: This blog has been put together by combining the incredible efforts, suggestions, and feedback from the ABAP platform PM team (Olga Dolinskaja), CoE expert (Subit Benny), and Solution advisory expert (Ruhi Naaz Quadari) when deciding on the extensibility of S/4HANA using the Clean Core concepts.