Migrating to SAP S/4HANA is one of the most significant steps a business can take in its digital transformation journey. However, the success of this migration largely depends on choosing the right implementation strategy. Two primary approaches dominate this space: Greenfield and Brownfield.

This article will guide you through the importance of choosing the right strategy and breaking down Greenfield and Brownfield implementations.

What is Greenfield Implementation?

A Greenfield implementation refers to a completely fresh start in deploying SAP S/4HANA. It involves building a new system from the ground up without carrying over configurations, customizations, or data from an existing SAP environment. This approach allows organizations to reimagine their business processes and adopt SAP's best practices as a foundation for the new system.

Key features include

• The opportunity for process redesign
• The elimination of technical debt
• The ability to fully leverage S/4HANA's advanced capabilities

It is particularly well-suited for complex systems where continuing to build on existing architectures would be inefficient or unsustainable.

What is Brownfield Implementation?

In contrast, a Brownfield implementation, also known as system conversion, involves upgrading an existing SAP ECC system to S/4HANA while retaining much of the current configuration, data, and processes. This approach focuses on transforming the underlying technology without overhauling the business processes.

Brownfield implementations prioritize continuity. Organizations convert their existing systems to S/4HANA, keeping historical data intact and minimizing Disruption to ongoing operations.

Key features include

• A faster rollout compared to Greenfield
• Lower initial costs
• Ability to maintain familiar processes.

This method is often chosen by companies that are satisfied with their current workflows and seek a more incremental transition to S/4HANA.

Key Differences Between Greenfield and Brownfield

The table below highlights key differences between Greenfield and Brownfield.

Features

Greenfield

Brownfield

System Architecture

Completely new system design

Upgrade of existing system architecture

Customization Flexibility

High with full redesign of processes possible

Limited to existing customizations retained

Time

Longer duration

Shorter duration

Cost

Higher initial cost

Lower initial cost

Risk and Disruption

Higher due to significant change

Lower due to continuity of operations

Process Innovation

High with opportunity for reengineering

Limited with a focus on retaining existing flows

Data Migration

Selective or no data migration

Full migration of historical data

Pros and Cons of Greenfield

Customers can install SAP S/4HANA directly, deploy it in the cloud or use hybrid combinations of the two. Because IT moves quickly in modern times, this aspect of cloud computing fits perfectly with strategies emphasizing scaling up, business continuity and digital change. Moving to S/4HANA makes it possible to use AI, machine learning, IoT and a variety of other new technologies to improve both operations and customer interactions.

How does SAP ECC migration occur?

Pros

Clean Architecture: Starting fresh eliminates technical debt and outdated customizations, resulting in a streamlined system.

Innovation: Organizations can adopt the latest S/4HANA features and best practices without legacy constraints.

Process Redesign: Offers the chance to reengineer business processes for greater efficiency and alignment with digital transformation goals.

Read: 5 Crucial Assessments for Seamless ECC to SAP S/4HANA Transition

Cons

High Cost: Building a new system requires a significant financial investment.

Longer Duration: The process of redesigning and implementing a new system takes more time compared to conversion.

Change Management Challenges: Employees must adapt to entirely new processes, which can lead to resistance and training needs.

Pros and Cons of Brownfield

Pro

Faster Rollout: System conversion is typically quicker than a full rebuild, allowing organizations to migrate to S/4HANA sooner.

Lower Risk: Retaining existing processes minimizes Disruption to business operations.

Retains Historical Data: All data from the legacy system is preserved, ensuring continuity for reporting and compliance.

1. System conversion (Brownfield)

This is a technical conversion of the existing ECC system to S/4HANA without changing the core business processes. It’s suitable for businesses that want to preserve their current configurations and customizations.

2. New implementation (Greenfield)

This involves setting up a new S/4HANA environment from scratch and redesigning processes based on best practices. It’s ideal for companies wanting to remove legacy baggage and reimagine their operations.

3. Selective data transition (Hybrid)

A middle-ground approach that allows selective migration of data and processes from ECC to S/4HANA. It combines aspects of both brownfield and greenfield methods.

The choice depends on the organization’s goals, current ECC usage, data quality, and risk appetite.

1. Project planning and governance 

As soon as the approach is chosen, the team moves on to planning the project. Individuals involved are SAP consultants, project managers, developers and those from the business. By having clear governance, everyone knows what needs to be done, by when and how success is measured.
Technology preparation, checking infrastructure, deciding how to move data, planning tests, training users, and supervising changes are all parts of planning. Keeping the steering committee updated through regular meetings allows the project to move forward with the business’s main goals in mind.

2. System preparation and custom code remediation

Testing is carried out on the ECC system prior to migration by means of SAP Readiness Check and SAP Transformation Navigator. They look for possible problems in custom code, interfaces and data structures that could cause difficulty with the migration process.
The S/4HANA data model is applied to custom code, which may be retired, modified or entirely rewritten. At this point, it’s important since there are many customizations in ECC systems, and they need to be handled with care.

3. Data cleansing and migration

ERP systems depend on data for success, and how good the data is can affect the outcome of the migration process. Before transferring data to S/4HANA, companies need to ensure that duplicate, inconsistent and old data are cleaned up in ECC.
When choosing among migration options, data may be transferred directly, loaded into a new setup or only a section is moved over (hybrid). These special tools are essential for smoothly moving data from one system to another.

4. Integration and testing

When migration is done, we ensure that the data connects properly to CRM, SRM, HR and third-party applications. Testing of critical processes covers the whole application to observe their correct results. This requires doing unit testing, system integration testing (SIT) and user acceptance testing (UAT).
Performance testing makes it clear that S/4HANA is able to function well at its best, and regression testing shows that existing workflows still operate properly after migration.

5. Go-live and post-migration support

At the go-live stage, the business transitions to using S/4HANA. Most of the time, it will take place over the weekend or during an established time off. The process of final data loads, validation and checking of the system is precisely organized and carried out.

Support after migration includes hypercare, during which IT and support teams watch the system, help users and tweak performance. After stabilizing, further efforts are made to fully make use of what S/4HANA can do.

Conclusion

The need to modernize, become agile and remain ready for the future has made migrating from SAP ECC a necessary strategy. With competition to stay ahead, S/4HANA gives businesses the tools, response and intelligence needed for success in the digital world.
It may seem challenging, but by carefully planning, enacting it correctly and aligning the organization, moving from ECC to S/4HANA can be achieved. Mere upgrades aren’t enough—they should work on redefining what the business does fundamentally. Industry leaders who adopt these changes as early and as carefully as they can stand a good chance of continuing to lead for many years ahead.

In today’s rapidly changing business landscape, VE3 is committed to empower organizations with the tools they need to thrive. As SAP prepares to end support for ECC by 2027, the urgency to transition to SAP S/4HANA becomes evident. At VE3, we understand the significance of this move and leverage our partnership with SAP to offer diverse solutions to guide organizations through a seamless migration. For more information contact us or visit us!