SAP S/4HANA: Greenfield vs. Brownfield Approach

AI This article was created with the help of AI.

What is the difference between Brownfield and Greenfield?

Migration to SAP S/4HANA is one of the key IT decisions of the coming years. When modernising your ERP landscape, you face a fundamental question: do you make a radical cut or do you focus on continuity? Generally speaking, companies have a choice between two classic migration paths and a hybrid middle way. The Greenfield approach refers to a complete new implementation of the SAP system on a greenfield site. Existing processes, legacy data and custom developments are discarded. Instead, you consistently align the ERP system with the new SAP Best Practices and the Clean Core philosophy.

In contrast, there is the Brownfield approach, also known as System Conversion. With this method, you convert your existing SAP ECC landscape directly to S/4HANA. The goal is to retain established business processes, historical transactional data and proven customisations. This reduces change for the business departments, but potentially carries forward technical debt.

Current market data illustrates the distribution in practice: According to a meta-study by SNP, which summarises surveys from Foundry, PAC, ASUG, DSAG and others, 39 per cent of companies opt for a system conversion (Brownfield), 27 per cent for the hybrid Bluefield approach and 26 per cent for a new implementation (Greenfield). Mixed and hybrid scenarios such as Selective Data Transition are thus gaining in importance, especially for complex corporate structures. Which path is the right one depends on your strategic goals and the experience of your SAP-Projektmanager.

What is the difference between FI and CO?

The finance modules are at the heart of every S/4HANA transformation, as financial data permeates all operational business processes. In the classic SAP ECC world, Financial Accounting (FI) and Controlling (CO) formed two separate worlds with their own data models, reconciliation accounts and table structures.

Financial Accounting (FI) vs. Controlling (CO)

The FI module is used for external accounting. It records all financial business transactions for external stakeholders such as tax offices, banks and auditors. This is where the balance sheet and profit and loss (P&L) statement are created in accordance with HGB or IFRS. The CO module, on the other hand, is oriented towards internal accounting. It supports management and department heads with operational corporate control, cost element and cost centre accounting, as well as contribution margin accounting.

• FI (Financial Accounting): Focus on external reporting, statutory accounting, general ledger, accounts receivable, accounts payable and asset accounting.

• CO (Controlling): Focus on internal reporting, cost centres, internal orders, product cost controlling and profitability analysis.

• S/4HANA Universal Journal: Merging of all FI and CO documents in the central ACDOCA table as a Single Source of Truth.

With the introduction of SAP S/4HANA, SAP dissolved this separation technologically: via the Universal Journal (table ACDOCA), financial accounting and controlling flow into a shared database, which SAP itself describes as a Single Source of Truth for external and internal accounting. This eliminates the need for time-consuming reconciliation work between FI and CO. For companies, however, this means that they need consultants who can think across processes and no longer isolate themselves to a single module. Given the complex accounting standards, experienced specialists are in demand, and the SAP Consultant Gehalt in the DACH market also reflects this broad FICO competence.

What SAP know-how the approaches require

The choice between Greenfield, Brownfield or Bluefield largely determines which skill profile your project team needs. A fatal mistake in resource planning is to treat S/4HANA expertise as a universal term. Greenfield projects require completely different methodological and technical skills than a Brownfield conversion.

Profile requirements in methodological comparison

• Greenfield requirement profile: Strong enterprise architects, business process engineers and Fiori/UI5 specialists for designing modern interfaces. Knowledge of the SAP Business Technology Platform (BTP) and the Clean Core principle is required.

• Brownfield requirement profile: Deep technical knowledge of the SAP Readiness Check, Custom Code Migration Worklist, ABAP/ABAP OO adaptations, cutover management and specialised tools for data cleansing.

• Bluefield requirement profile: Functional expertise for Selective Data Transition, transformation tools and complex migration mapping logic.

The market pressure on these niche skills is intensifying exponentially. Regular mainstream maintenance for SAP ECC ends on 31 December 2027. Although SAP offers extended maintenance until the end of 2030 for an additional fee, the acute shortage of available migration specialists makes waiting an incalculable business risk.

Staffing S/4HANA roles: Permanent or Freelance

When planning an S/4HANA migration project, you face the challenge of securing your core team for the long term while maintaining the flexibility to cover temporary project peaks. A pure permanent recruitment strategy is often too slow for tightly scheduled cutovers, while a pure freelance setup puts long-term in-house knowledge at risk. The optimal solution lies in a balanced staffing strategy.

Staffing models in the S/4HANA project

We at Nova Search support you exactly at this interface: Whether you are looking for strategic in-house consultants for Festanstellung (Permanent Recruitment) or need short-term capacity via Freelancer & Vertragsbesetzungen. With our database of over 1,500 pre-qualified SAP profiles in the DACH region, we avoid time-consuming CV noise. Through our two-stage screening process consisting of a technical deep dive and a cultural interview, you will receive the first qualified profiles on your desk in 5 working days for permanent positions, and verified freelancer profiles within 48 hours. Furthermore, we carry the risk with our contractual 90-day guarantee so that your project remains on course both in terms of time and expertise.