Warburtons’ S/4 HANA Brownfield Implementation Journey

At UKSUG Connect 2024, Simon Green, Hitesh Patel, and Elizabeth Green covered Warburton’s move to S/4 HANA. The project was especially interesting because of the extremely short downtime involved for key operations — just 4.5 hours.

Overview of Warburtons:

Warburtons is a fifth-generation family business transitioning to the sixth, renowned as the most chosen brand in Great Britain. Baking over 2 million products daily and delivering them to 18,000 stores by 4:00 am, the business operates with near-zero downtime. SAP ECC 6 served as their “central nervous system,” making uninterrupted operations a critical necessity.

Project Objectives:

The implementation of S/4 HANA was essential for Warburtons to:

• Future-proof their IT core with minimal downtime.
• Complete the upgrade within 24–36 hours over Easter, leveraging reduced operational activity.
• Minimize resource usage and impact on business processes.

Business Benefits:

• Migrating early avoids the 2027 support deadline rush and retains in-house SAP expertise.
• S/4 HANA provides a foundation for enhanced business processes and user interfaces.
• The project was timed to align with necessary hardware upgrades, ensuring sustainability until 2040.

Implementation Highlights:

The two-year project encompassed:

1. Hardware Upgrades: Concurrent system and hardware updates streamlined processes.
2. Global Collaboration: Partnering with NTT’s UK and Indian teams ensured robust support.
3. System B Creation: A backup system allowed core functions to operate during migration, limiting SAP downtime to just 4.5 hours for bakeries and distribution.
4. Proactive Planning: Early customer order management and production scheduling prevented disruptions.
5. Change Management: Utilizing a 250-strong super-user network facilitated training, engagement, and communication across all sites.

Lessons Learned:

People:

• Utilize a Change Network: Leveraging Warburtons’ super-user network streamlined communication and reduced complexity.
• Manage Expectations: Framing the migration as a foundational upgrade minimized resistance.
• Early Preparation: Implement changes progressively to reduce go-live stress.

Process:

• Simplification List Preparation: Starting early with Customer/Vendor Integration (CVI) and similar tasks avoids last-minute challenges.
• Conversion Cycles: Conduct dry runs with the same resources as live migration to refine processes and timelines.
• Late Locking: Necessary for high-volume material movements to mitigate performance hits.

Technology:

• Performance Testing: Uptime migration was resource-intensive, requiring careful performance tuning to manage peaks and troughs.
• Cross-Team System Access: Allocating time for both functional and technical testing is crucial, covering aspects like AV, firewalls, and disaster recovery.
• Iterative Approach: Multiple test iterations increased confidence, optimized playbooks, and resolved technical bottlenecks.

Results:

Warburtons successfully transitioned to S/4 HANA over Easter weekend with minimal business disruption, handing back a fully operational system by Sunday. The migration positions the company for sustained growth and innovation, with SAP support secured until 2040.

Quote: “We now have a product that is fit for the future and will support the next five years of business.”

Change Management and People Aspects

My favorite part of the presentation came from Elizabeth Griffin, IT Org Change and Training Manager at Warburtons, who emphasized the extensive efforts undertaken around people and change management.

Overview:

Elizabeth Griffin highlighted the pivotal role of change management in ensuring the success of Warburtons’ S/4 HANA migration. The project emphasized clear communication, early engagement, and leveraging existing internal networks to minimize resistance and ensure smooth adoption.

Key Strategies:

1. Leveraging the Super-User Network:
   Warburtons’ 250-strong super-user network, spread across all sites, played a vital role in communication, training, and testing. These individuals were the primary points of contact for their respective teams, driving change from within.
   Quote: “Having this super-user network meant that something complex like S/4 felt straightforward.”
2. Tailored Communication Plans:
   Separate communication plans were developed for each of Warburtons’ 26 sites, tailored to the specific needs and preferences of each function.
   Quote: “We ensured everyone knew exactly what was happening by go-live weekend—no surprises, no confusion.”
3. Minimized End-User Impact:
   Changes were rolled out progressively. Many transactions already existed in ECC, allowing users to familiarize themselves with new processes months before the actual migration.
   Quote: “We ensured changes were incremental, so by go-live, it felt natural to users.”
4. Expectation Management:
   The project was framed as a technical upgrade rather than a transformational change, setting realistic expectations among employees.
   Quote: “This was about creating a platform for future benefit—not introducing sweeping changes today.”
5. Proactive Engagement:
   Detailed change impact assessments were conducted at organizational, team, and individual levels. Plans were created to guide individuals from their current state to the desired state post-migration.
   Quote: “We mapped the journey for individuals—where they were and where they needed to be.”
6. Comprehensive Enablement Plan:
   Training and support for new processes began months in advance. During the go-live weekend, super-users provided on-the-ground support, working late and even coming in during holidays to ensure a smooth transition.
7. Sustaining Change Post-Go-Live:
   Post-migration, Warburtons focused on supporting users to ensure changes stuck and systems were used effectively.

Lessons Learned:

1. Build and Empower a Change Network:
   Super-user networks are invaluable for cascading information, fostering local ownership, and reducing resistance to change.
2. Manage Expectations:
   Clearly communicate the nature of the change to prevent disappointment or misaligned expectations.
3. Start Early:
   Implement incremental changes to reduce the impact at go-live, giving users time to adapt.
4. Individualized Impact Assessment:
   Breaking change management into organizational, team, and individual levels ensures tailored support and higher adoption rates.
5. Support Sustained Adoption:
   Continued post-go-live activities are essential to embed changes fully and address lingering challenges.

Quote: “Change management wasn’t revolutionary, but it was essential—supporting the team every step of the way ensured success.”

This structured and people-centered approach was critical to the project’s overall success, turning a potentially disruptive migration into a seamless experience for the organization.