Enormous 15-hour Migration to SAP S/4HANA®


“We had to migrate two exceptionally large ERP systems – the cores of our merchandise management system in Switzerland – at the same time on one weekend. Downtimes lasting several days were not an option. The migration using SNP’s BLUEFIELD™ approach went smoothly – and even came in under the original time estimate.” Stefan Gempp, Head of IT Systems for Purchasing/Master Data/Promotions, Coop

At a Glance

The Challenge

Coop commissioned SNP to migrate the two ECC SAP systems CCR and CTC to S/4. The two systems consist of a 56 TB retail system (CCR) and an 8 TB trading system (CTC). These systems are extremely important for Coop and both are business-critical, as 50 percent of sales are processed through them. However, both systems had already been running for many years: one for 20 years, the other for 12 years. They needed to be migrated to S/4 at the same time, using the NZD approach (Near-Zero Downtime) for the large CCR retail system. This approach was crucial because the downtime for both systems was limited to 18 hours only.

The Benefits

  • CrystalBridge® transformation platform for guided, end-to-end project planning (standardized, automated)
  • Several projects combined into one
  • Selective data migration by transferring only the required historical data
  • Reduced staffing / consultant days
  • Less risk: The current SAP landscape is not changed during the migration (fallback option)

The Solution

Coop’s two ECC systems – retail (SAP CCR) and trading (SAP CTC) – spanned the areas of category management, merchandising, procurement, logistics, sales and promotions. Both systems had already been running for many years – 20 years and 12 years respectively – and had been extensively adapted, with many in-house developments and interfaces (> 400). All interfaces had to be checked in advance.

Coop decided to transfer only the last two years of data to the new system, with older data continuing to be available to users on read-only systems. Custom code checks and SAP simplification item checks were very important at this stage. First, the migration team created an empty shell system with release 2020. The custom code was fully implemented in this version, and the resulting “golden system” formed the basis for the production migration.

An initial migration for the CCR system took place one week before the downtime migration. In the following week, a delta migration was performed every day, which allowed SNP to migrate a smaller data set within the downtime on the go-live weekend. After three test migrations and a go-live simulation, the 18-month project was successfully completed as planned, and the systems went live after only 14 hours of downtime.

Key Facts

Project Type

Move to SAP S/4HANA®


  • Hardly any noticeable disruptions to purchasing, disposition and CCM processes on the retail and trading systems during or after the go-live.
  • Three weeks later, 1.8 million purchase orders and 340,000 sales documents had already been processed.


< 50,000

Countries involved




Data size

Retail system (CCR): 56 TB, Trading system (CTC): 8 TB


  • Migrating the SAP ERP systems CCR and CTC to S/4HANA using SNP’s BLUEFIELD™ approach
  • Retroactively merging transaction data and data in FI/CO only up to the defined key date
  • Implementing the New GL without a document split
  • Creating business partners as organizations


SNP Products

  • CrystalBridge® – The Data Transformation Platform

  • SH (Shell)
  • Et (Empty Target System)

About Coop



Basel, Switzerland


CHF 31.9 billion (2021)





The Coop Cooperative is one of Switzerland’s largest retail and wholesale companies. The cooperative has around 2.5 million members and 95,000 employees. Coop operates supermarkets, department stores, restaurants, pharmacies, gas station stores and convenience stores. In their online stores “coop.ch” and “Coop-City.ch,” customers can order products from the Coop product range directly to their homes. The Coop Group also includes DIY stores (jumbo.ch), furniture stores (livique.ch), electronics stores (interdiscount.ch), perfumeries (impo.ch), and watch and jewelry stores (christ-swiss.ch).