Three steps from a „dirty“ SAP system back to a core system that complies with standards

Even in the early days of standard software, software providers fought for clean code. For example, there was a programming rule: in-house developments only start from line 50,000! Surprisingly, this principle is still relevant today. SAP addresses this challenge for code and business processes with its Clean Core initiative: The standard remains untouched, customer specifications are neatly encapsulated – consistently implemented with a platform strategy on the SAP BTP (Business Technology Platform).

The goal is to create a stable core: essential processes run in a standardized, highly automated, and cost-efficient manner. Separate from this is an innovation layer: enhancements and differentiation are created in a modular, fast, and flexible manner outside the core—preferably on the BTP. Security and compliance aspects are also taken into account: fewer individual interventions mean fewer vulnerabilities and easier compliance with regulatory requirements.

This raises key questions for user companies: Where are we today—and how do we get to Clean Core? The three steps outlined below provide a sensible approach and point to helpful methods and tools (from SAP and partners).

Step 1: Tool-supported code analysis (bottom-up)

First, in-house developments must be evaluated. The following SAP classification of „clean core extensibility“ into four levels serves as a target criterion for future enhancements.

• Level A – Ideal: Use of public interfaces with stability contracts only.
• Level B – ProvenUse of established APIs and classic SAP technologies.
• Level C – Limited: Read access to internal data objects.
• Level D – Critical: Extensions or modifications that are not recommended.

When clearly defined in technical terms, classification provides a solid basis for systematic consolidation. The following SAP tools can help with this:

• ABAP Test Cockpit (ATC): Classification of in-house developments, identification of rule violations and „technical debt.“.
• Readiness Check (including simplification items)Identifies functions or artifacts that are eliminated, replaced, or transformed with S/4HANA.

Partner solutions provide additional benefits:

• smartShiftAutomated evaluation and „restructuring“ of customer-owned code – including usage reference.
• IBIS Prof. Thome: Comprehensive evaluations and assigns extensions used to technical process contexts using machine learning.

Step 2: Process and fit-gap view (top-down)

Once you have reached the process level, the next key question arises: Is a special process really necessary, or can it be brought back into the standard? The Clean Core Initiative has two clearly separated layers:

• core processes are primarily designed via Configuration/Central Business Configuration (CBC) to ensure compliance with standards.
• A few, clearly justified special processes are implemented as extensions to the BTP – only where there is genuine benefit or a competitive advantage.

The desired clean core for processes thus simplifies innovation: continuous improvements can be rolled out more quickly.

While custom code can still be assessed fairly well using technical analyses, it becomes much more challenging when it comes to organization-specific business processes. What is needed is a so-called fit-gap analysis, which brings together current process usage, technological possibilities, and company requirements. Fit-gap analyses check whether the current form of the process variants used ...

• on incompatible technology based (to be replaced by S/4HANA functionality or BTP apps),
• overly complex is or
• unorthodox customization contains, which is not viable in cloud-based clean core processes.

Readiness check process analyses, SAP Signavio, and other partner solutions provide assessments here; SAP Best Practices define the clean core target vision.

Step 3: Leveraging master data used in processes

Master data quality is often overlooked in traditional process analyses, yet it is crucial for clean processes. SAP partner IBIS Prof. Thome closes this gap by focusing on master data, which is often criminally neglected. The analysis examines the following questions in particular:

• Which master data is relevant in which processes?
• Do the existing parameterizations correspond to the actual process usage?
• In which areas is it useful to simplify master data parameters?

In addition to examining process usage and data consistency, cleaning up and archiving unused master data can also make a significant contribution to improving data quality.

• IBIS Prof. Thome has developed a five-level classification system specifically for this purpose, covering master data objects (materials, business partners, etc.) and their use in processes – analogous to the enhancements:
• A = active use in clean processes (public cloud-ready)
• B = Use in customized variants (Z customizing; CBC mapping possible)
• C = Use in processes with innovations (e.g., S&OP → IBP)
• D = Process used not applicable with S/4HANA or highly customer-specific → Revision necessary
• E = Use unclear → manual analysis

All three steps are important.Code analysis alone is not enough. Process and master data evaluation are equally important „cleaning agents.“.

Benefits for IT and specialist departments

Faster innovation: Continuous improvements, rapid adoption of new AI capabilities.

• Lower TCOReduced maintenance and operating costs, simplified upgrades.
• Robust governanceLess dispersion, greater transparency, improved auditability.
• safety gainReduced attack surfaces.

practical guide

1. Classify: Assign to extensibility levels A–D; form risk clusters.
2. Check process fit: Compare with SAP best practices and target process map; document fit gap.
3. Evaluate master data: Data profiling; classification A–E; define cleanup and simplification plan.
4. Deciding: Standard vs. individuality as a mindset decision – business case for each deviation.
5. Transform: Refactor/decouple to BTP, configuration via CBC, clean up, archive.
6. Establish governance: policies, quality gates, lifecycle management.