3 Paths to S/4HANA, not 2!

You’ll hear “greenfield” and “brownfield” used in common conversation about transitioning from ECC 6.0 ERP to S/4HANA. These two words — and too few words — cause more confusion than clarity.

To be clear, there are three scenarios for moving to SAP S/4HANA:

  • New Implementation
  • System Conversion
  • Selective Data Transition

The first two receive wide attention, but the last is thought provoking.

After sorting out the the business case — the WHY — of moving from ECC 6.0 to S/4HANA, it’s time to think about HOW. You’ve probably read a lot about two options: “New Implementation” versus “System Conversion.” That’s all I ever read about! But those two are one option short of a whole story.

Selective Data Transition — the third option — is a strategy with options that fits in the middle and warrants your attention.

For one thing, you need to be aware of all the options on the table. But there’s much to like here because Selective Data Transition properly focuses your S/4HANA transition conversation on … data. No matter which path you eventually choose for transition, you’ll profit from that focus.

SAP Data Management & Landscape Transformation (DMLT) is a collection of service offerings aligned with selective data transition, new implementation, and system conversion.

I’m not selling services here; I’m saying that the ideas discussed in Selective Data Transition are rich content that you might richly profit from considering. There’s value to be had whether you engage services, incorporate concepts into your specific transition plan, or simply focus on master data as the foundation of Digital Transformation.

New Implementation

This option is a conventional implementation of SAP S/4HANA from scratch.

An astonishing number of euphemisms beyond “greenfield” are employed to avoid using the words “New Implementation.” But here it is in broad strokes:

  • Create a new SAP S/4HANA system.
  • Manually configure Business Processes.
    • Time-saving reference: One or more Model Company systems.
    • Time-saving reference: SAP Best Practice content.
  • Execute data migration for initial data load from legacy systems.

This option is typically favored when:

  • Implementing fundamental business process re-design.
  • Significant data cleansing required.
  • Significant data transformation or data construction required.
  • Historical data not required (only master data and open items).

System Conversion

This option is a technical conversion of an existing on-premise ECC 6.0 (SAP Business Suite) system into an on-premise SAP S/4HANA system.

SAP S/4HANA ERP is not the successor of SAP Business Suite, so we we use the term “system conversion” rather than “upgrade” for this scenario.

This option is typically favored when:

  • Full business process reuse, adjusted for S/4HANA simplification.
  • Very limited data cleansing required.
  • Limited data transformation or data construction required.
  • Phased go-live is not required.

Selective Data Transition

All S/4HANA transition options have to consider Business Process implementation (configuration) and data (both master data and transactional data). But a conversation about Selective Data Transition immediately sharpens the focus on data.

This is an approach with options, not just one fixed scenario.

We’re talking about a strategy that fits neatly between New Implementation and System Conversion, with a range of options that you choose from to suit your particular circumstances.

There are two common approaches to create a target system with Selective Data Transition: Shell Conversion and Mix and Match.

In Shell Conversion, a shell copy of a production system is made without master and transaction data and this is converted to SAP S/4HANA. In Mix and Match, a new S/4HANA install is created and then elements of the existing configuration and ABAP repository are transported or manually transferred.

Both scenarios require data migration to follow including master data, balances and open items.

Blog: Move to SAP S/4HANA with Selective Data Transition

It’s an interesting strategy, making accessible some of the benefits of New Implementation and relieving some of the constraints of System Conversion.

Credit: Blog: Move to SAP S/4HANA with Selective Data Transition

Shell Conversion

Shell Conversion process steps.

A copy of a production system is made without master and transactional data. If the source system was less than the last release of ECC 6.0. or not Unicode, then an upgrade is performed. Lastly, a system conversion takes place, with the result being an S/4HANA system with ECC 6.0 business processes configured, development objects in place, and no data.

Depending on your objectives, this might make a good start. The next steps are to make adjustments for S/4HANA and any new business processes.

The S/4HANA shell is typically used as S/4HANA development system and the source to build your S/4HANA target production system (via system copy).

This path also affords an opportunity to address data quality before migration data to the target system.

Mix and Match

If the scope of new business processes in S/4HANA or enhancement in ECC 6.0 makes renders the legacy system a less-than-attractive starting point, then the Mix and Match option skips Shell Conversion step in favor of beginning with a clean S/4HANA system.

This might appear to be “New Implementation” path, and it is, but with important accelerators.

A combination of reference systems can speed business process configuration. These include the legacy ECC 6.0 system, SAP Model Company systems, and Best Practice content. The point is, experience and reference system propel business process configuration.

Data Migration

Data migration scope can be determined by business object, with or without selective historical data.

SAP Data Management & Landscape Transformation (DMLT) content and processes have been developed to migrate master data and time-sliced historical data.

Moreover, all conventional data migration approaches remain available for use where appropriate.

Compare and Contrast

Comparing option for System Conversion with Selective Data Transition.

ItemSystem ConversionSelective Data Transition
Intention for ERP Template Reusability As much as possible.More than ~70% 
Intention for new processes NoYes 
Data Migration: Master Data & Open Items Only No Yes
Data Migration: Historical Data Yes, full Yes, full & selective history
Custom programs & relating ABAP objects Yes, full Yes, full
Roll-Out: Big-Bang Yes Yes
Roll-Out: Phased No Yes
Deployment On-Premise / PAAS YesYes 
System Conversion Prerequisites: Unicode Conversion, ArchivingOne Go-Live not possible and conversion has to be a 2 Step process with current downtime and data reduction requirementsOne Go-Live possible (due to separate system)
Risk Mitigation: Planned time for executing Fall-Back Plan during cut-overMedium-Long (system restore in standard scenario to be planned)Short (no system restore needed)
Optimization of Downtime during cut-over Available with NZDTUp to 2 Days based on Data Size
Solution Maturity / Customer ExamplesMany examples exists for standard SUM, NZDTSLO process for Shell Creation & Data loads are proven methods. Using this approach for S/4 is new.

How to choose?

Plot the answers to 5 key questions.

A: Business Process Transformation?

What is the grade of required Business Process re-engineering in the future target system?

  1. Low
  2. Medium
  3. High

B: How Much Data?

How much data is required to move to the future target system?

  1. All data, including history.
  2. Selective historical data / organizational slice / time slice.
  3. Master Data and Open Items

C: How Many Systems?

What’s the Source-Target system ratio? How many ERP, Legacy, and non-SAP systems and how many To-Be S/4HANA systems?

  1. Source and Target are the same system.
  2. One Source and one Target system.
  3. N:M System Split or Consolidation.

D: Deployment Options

How will your future systems be deployed?

  1. On Premise (includes hyperscaler)
  2. Two-Tier (On-premise + SAP Cloud / hyperscaler)
  3. SAP Cloud

E: Roll Out Options

How will your future systems be rolled out?

  1. Big Bang (1 go live)
  2. Phased by Business Unit / Org Unit
  3. Phased by LoB / Application