Choosing the Right Migration Strategy Towards S/4HANA

As organizations modernize their operations, migrating to SAP S/4HANA has become a critical step in realizing the full value of digital transformation. But with high complexity, steep investment, and growing pressure from the 2027 ECC deadline, choosing the right migration strategy is essential. Whether you're evaluating greenfield, brownfield, or hybrid options, success depends on early planning, robust testing, and a clear understanding of the risks and rewards tied to each approach. This blog outlines key migration decisions—and how to align them with your business objectives to drive long-term ROI.

Understanding Migration Complexity and Key Considerations

Migrating from SAP ECC to S/4 HANA is no small task. It requires a strategic approach that encompasses both technical and business objectives. Organizations need to decide on the scope and phasing of the migration, as well as the resources and tools required. With 74% of projects experiencing significant delays, carefully evaluating migration options and ensuring thorough testing can prevent costly setbacks. Careful testing will also mitigate unforeseen costs, including post-go-live issues, scope reductions, and critical fixes, all requiring hypercare. Many organizations report spending a third of their entire migration budget on testing alone. However, with effective test planning, shifting testing left in the SDLC, and SAP test automation tools like Tricentis Tosca and LiveCompare, which enable automation and a more risk-based approach, organizations can not only spend less on testing, but, more importantly, deliver higher quality software, with fewer defects, faster. 

On-Premise vs. Cloud: an essential decision

Moving from an on-premise system to a cloud-based one is one of the fundamental choices organizations need to make. While public cloud environments offer scalability, accessibility, and lower CapEx, certain industries or regions are more hesitant, or simply unable, to adopt public cloud services, especially where data privacy and regulatory requirements are stringent. Canada, for instance, tends to be more risk averse, with organizations often preferring to wait and observe the outcomes of early adopters before making the leap to the public cloud.

To bridge the gap, many companies either implement S/4 HANA on-premise or in a hosted model, while others are opting for hybrid solutions that combine on-premise and cloud resources. This approach allows of gradual cloud integration, providing the flexibility to move critical workloads and data over time, while enabling a smoother transition and compliance with regulatory needs. 

Greenfield vs. Brownfield: tailoring the migration approach

Choosing between greenfield and brownfield migration is another critical decision. Both approaches offer distinct advantages and drawbacks, and the choice largely depends on the organization’s existing infrastructure and strategic goals.

Greenfield: starting afresh

Greenfield implementations allow organizations to start with a clean slate, configuring SAP S/4HANA according to current and future needs. This approach supports modern, innovative features and customization but requires a significant resource investment. A greenfield migration may extend project timelines due to comprehensive reconfiguration, data migration, and employee training requirements. However, the long-term benefits of aligning the system with evolving business requirements often outweigh the upfront investment.

Brownfield: leveraging existing systems

Brownfield migrations enable companies to retain existing processes while upgrading to SAP S/4HANA. With this approach, timelines tend to be shorter, and there is less disruption, as employees and systems are already familiar with core functionalities. However, companies opting for brownfield migrations may find it challenging to leverage the full capabilities of SAP S/4HANA if their legacy systems are outdated. If their SAP is highly customized, they will spend extra time reworking these customizations for the new platform. For organizations with well-established ERP processes and minimal change requirements, brownfield offers a practical and cost-effective path.

SAP migration testing is key

An effective SAP S/4 HANA testing strategy comprises data integrity, functional compatibility, and system performance. At TTC Global, we emphasize testing at each stage, including performance, data validation, and infrastructure readiness. Key tools like Tricentis Tosca and qTest offer automated testing solutions and test management that enhance accuracy and reduce human error, while risk-based approaches (for instance through the use of LiveCompare) help pinpoint high-impact areas for focused testing efforts.

One significant testing challenge in migration is ensuring data accuracy during the transition. Even a minor data discrepancy can lead to costly errors, as illustrated by an instance in which a misplaced decimal point caused millions in losses. To avoid such issues, automation tools can minimize manual interventions, reducing the risk of such high-stakes errors while maintaining data integrity throughout the migration.

Performance and security testing

In cloud environments, performance and security concerns require close attention, especially since cloud migrations introduce new variables, such as latency and failover protocols. Testing in cloud-based environments must also align with cloud security standards and data protection requirements, which differ from on-premise environments. Utilizing specialized testing approaches ensures smooth system performance and robust security, addressing any latency or compatibility issues that may arise post-migration.

Business Process Re-evaluation: a golden opportunity

SAP S/4HANA transformation offers a strategic opportunity to revisit and optimize core business processes. Tools like SAP Signavio facilitate business process mining, enabling organizations to reassess workflows and eliminate redundancies before transitioning to a new system. By avoiding a ‘lift and shift’ approach and instead optimizing business processes ahead of migration, organizations can streamline workflows, reduce inefficiencies, and improve the overall ROI of the new system.

However, few organizations reach maturity levels that enable such proactive process mining. When I visit organizations, I have the impression that most companies are at intermediate levels of quality maturity. Achieving higher maturity can lead to substantial cost reductions and improved efficiency, emphasizing the value of process optimization in parallel with ERP migrations.

Large-scale migration? Go for a phased approach

Many organizations choose to adopt a phased rollout approach to manage the complexity of large-scale migrations. By migrating specific business units or regions incrementally, companies can implement lessons learned from earlier phases into subsequent rollouts, effectively ‘eating the elephant one bite at a time.’ We have successfully used this approach for a Texas-based energy company with a global network, significantly reducing migration timelines by addressing regional requirements one at a time.

Phased rollouts not only enable early identification of potential issues but also facilitate smoother change management, allowing companies to adjust and recalibrate based on initial outcomes. This strategy is particularly useful for multinational corporations with diverse regulatory and operational needs across different markets.

Best practices for a smooth migration

1. Early planning and phase-zero preparation: Initiating migration discussions early helps align project timelines, budget, and resource allocation with realistic expectations. A phase-zero assessment can uncover potential blockers and prepare the organization for an efficient migration journey. In some cases, a more in-depth approach—such as a Quality Maturity Assessment—may be valuable to evaluate testing readiness and quality processes before migration begins.
2. Comprehensive testing: Testing should cover all aspects of the migration, from data accuracy to infrastructure performance. Automated testing tools reduce the burden of manual checks, ensuring consistency and minimizing risks.
3. Engagement with expert partners: Partnering with experienced testing firms, like TTC Global, brings specialized knowledge and a laser focus on quality, offering tailored solutions that align with both global and local needs.
4. Adoption of automated and risk-based testing: Automation accelerates testing processes and supports long-term system maintenance post-migration. A risk-based approach ensures critical functions are prioritized, safeguarding core operations.
5. Change management and training: Providing training and support to employees is essential, particularly in greenfield implementations where new processes are introduced. An incremental rollout approach also helps manage change by reducing the immediate learning curve.

ENGAGEMENT WITH EXPERT PARTNERS

Choosing the right partner—one with the right depth of experience and a clear focus on quality—is critical to the success of any SAP S/4HANA migration. TTC Global brings unmatched expertise in SAP transitions, with decades of hands-on experience across industries and project types. Unlike larger service providers, we specialize exclusively in testing and quality engineering, offering independent, unbiased guidance and tailored solutions that align with both global standards and local needs.

Our proven methodologies and robust toolset—including the SAP Accelerator Pack, S/4HANA Quality Engineering Readiness Assessments, and leading automated testing solutions—equip organizations to manage complexity with confidence. Backed by a flexible, global delivery team, we help clients execute both greenfield and brownfield migrations with greater speed, less risk, and better outcomes. With TTC Global, organizations gain a focused, reliable partner to help ensure their SAP migration stays on track, on time, and aligned with business objectives.