In today's rapidly evolving digital landscape, staying ahead of technological advancements is no longer optional—it's a strategic imperative. Enterprise Resource Planning (ERP) systems, the backbone of many organizations, are under increasing pressure to deliver agility, intelligence, and scalability. With SAP announcing the end of support for ECC in 2027, companies are faced with a pivotal choice: remain on a legacy platform or embrace the next-generation capabilities of SAP S/4HANA. This decision is not just about technology—it’s about future-proofing the business.

This case study examines how KPMG Belgium supported a leading Belgian telecommunications (Telco) company in navigating this critical transition. It showcases how the migration to SAP S/4HANA was not only a technical upgrade but also a catalyst for broader business innovation, enabling the company to streamline operations, improve data-driven decision-making, and lay the groundwork for future digital initiatives.

Business context

This Belgian Telco, with over €5 billion in revenue and more than 10,000 employees, had relied on SAP ECC for 30 years. The system expanded to include four separate SAP instances and over 600 interfaces, leading to extensive custom code and non-standardized processes. Operating in a challenging environment with tight margins and a complex IT landscape, the company recognized the need for modernization. The board decided on a brownfield conversion to SAP S/4HANA, despite initial resistance from business teams.

The challenge

We were tasked with creating a clear vision for the SAP S/4HANA migration, addressing several key objectives:

  • Aligning business and IT teams: Bridging the gap between business and IT by setting shared expectations for the migration;
  • Demonstrating business value: Highlighting the tangible benefits of the brownfield conversion;
  • Creating a Target Application Model (TAM): Defining a roadmap for implementation;
  • Developing a data migration strategy: Deciding which data to migrate and how to manage it;
  • Addressing interface complexity: Managing and converting over 600 interfaces; and
  • Providing tangible guidance: Outlining preparation and execution steps for business and IT teams.

Approach and methodology

Our structured approach involved a 13-week comprehensive assessment divided into four key phases:

  1. Diagnostic analysis: Using tools like SAP Readiness Check and Signavio Process Insights, KPMG analyzed the existing SAP ECC environment, identifying areas for improvement and necessary adjustments for compatibility with SAP S/4HANA;
  2. SAP S/4HANA labs: Workshops addressed key pain points and explored SAP S/4HANA’s capabilities, fostering consensus among stakeholders and prioritizing business improvements;
  3. Roadmap development: KPMG developed a TAM to serve as a blueprint for digital transformation, assessing various migration scenarios to balance business continuity with cost efficiency; and
  4. RFP preparation: Consolidating findings into a comprehensive RFP document, enabling the Telco Company to solicit bids from system integrators effectively.

Stakeholder engagement

Effective stakeholder management was crucial. The ERP transformation had been a topic of discussion for many years, and various stakeholders had distinct expectations:

  • Management and Board Members: Prioritized a cost-efficient transition while ensuring agility.
  • Business teams: Saw the migration as an opportunity to optimize processes.
  • IT team: Focused on technical aspects and maintaining system operations.

Our SAP team balanced these diverse expectations, fostering alignment and trust across the organization.

Key results and impact

We successfully guided the Telco company from a fragmented landscape to a unified vision for SAP S/4HANA migration. The deliverables enabled the company to move forward with confidence, leveraging a robust RFP to engage system integrators effectively. KPMG continues to support the company as a trusted advisor during the implementation phase.

Lessons learned and best practices

Implementing a new ERP system is a significant project. Key considerations include:

  • Maximize S/4HANA’s business value: Simplify and standardize processes, leverage analytics, machine learning, and Fiori UX;
  • Ensure data quality and readiness: Cleanse and prepare data pre-migration, use SAP tools like Migration Cockpit;
  • Minimize customizations: Adopt SAP standard functionalities to reduce complexity;
  • Prioritize change management: Engage employees early, communicate benefits, and provide tailored training;
  • Plan for business continuity: Minimize disruption with careful planning and establish contingency plans; and
  • Onboard a team with relevant experience: Ensure effective communication across all roles.

The Road to SAP S/4HANA

With mainstream support for SAP ECC ending in 2027 (and extended support available until 2030), many organizations are reaching a critical decision point about the future of their ERP landscape.

Some are re-evaluating their long-term relationship with SAP, debating whether to remain on the platform or explore other options.

Others are weighing the benefits of using the shift to SAP S/4HANA as a catalyst for broader business transformation versus opting for a more straightforward technical upgrade to maintain support.

Our approach offers a balanced path—bridging system conversion with meaningful business transformation—tailored to each organization's unique goals and readiness.In this case study, we outline our proven framework to help you Define, Plan, and Deliver a successful SAP S/4HANA migration.