Practical Guide to Data Migration with SAP S/4HANA Migration Cockpit

2.2 Options for transitioning to SAP S/4HANA

There are three different scenarios for transitioning to SAP S/4HANA, as shown in Figure 2.1:

1. System conversion

2. New implementation

3. Landscape transformation

Figure 2.1: Options for transitioning to SAP S/4HANA

2.2.1 System conversion

A system conversion scenario for transitioning to SAP S/4HANA can be viewed from a concept perspective at least as similar to an upgrade but it is NOT an upgrade (see Figure 2.3). A system conversion can be viewed as a complete technical conversion of an existing SAP Business Suite ERP system to SAP S/4HANA. With this approach, you convert your current ECC system to the new SAP S/4HANA system. This approach can be adopted only on-premise and could be done either in an organization’s own data center or as part of an Infrastructure as a Service (IaaS) model.

An S/4HANA system conversion requires no (real) data migration (i.e., no physical extraction or transformation is required). Instead, a technical data migration that migrates elements such as the material ledger and transaction data to the universal journal as part of the post-S/4HANA conversion step is performed, as shown in Figure 2.2. For those not conversant with the terminology, the universal journal is a ledger of all accounting entries of business transactions in Finance (FI) and Controlling (CO) and it represents the single source of truth in SAP S/4HANA.

Figure 2.2: Migration as part of an S/4HANA conversion

Figure 2.3 provides a diagrammatic representation of the process for converting an existing SAP ECC system, with the steps typically involving:

• Database migration from a non-HANA database (AnyDB) platform from SAP ERP 6.0 and above, and from an SAP HANA database to an SAP S/4HANA database
• Conversion of the data model from ERP core (SAP Business Suite ERP 6.0) to SAP S/4HANA core, or from SAP S/4HANA Finance (formerly known as Simple Finance) to SAP S/4HANA
• Conversion of old application code and tables to new applications and structures; this also includes adapting the customer’s custom code so that it is compliant with the new data structures
• Creation of compatibility views (known as Core Data Services (CDS) views) to make the old reports and interfaces still function as normal
• Configuration adaptation in the areas of master data, the Financials, Logistics, Human Resources, Portfolio and Project Management, Procurement, Sales and Distribution modules, as well as industry-specific functions (for example, in New Asset Accounting, additional currencies, parallel valuation, material ledgers, etc.) based on the SAP simplification list (see Section 2.3 for further information on the simplification list)
• No forced migration from Classic GUI to Fiori except where transactions are no longer supported in GUI (refer to the simplification list)

Figure 2.3: System conversion

Why choose this option?

Choose this option if your organization’s strategic goal is to:

• Bring existing processes to the new platform
• Perform a complete technical conversion of the existing SAP ERP system to SAP S/4HANA
• Keep investment in custom code and technical debt
• Mitigate the risk and investment involved in a big-bang conversion project
• Retain recent investment in SAP Business Suite, with no business need to transform existing processes
• Adopt innovation at the organization’s own pace
• Adopt SAP Fiori for SAP S/4HANA to enhance user experience, mobility, and flexibility at the organization’s own pace

You should also choose this option if your organization has no strategic vision for migrating its SAP system to the cloud.

2.2.2 New implementation

A new implementation (or re-implementation, as it were) is where an organization chooses to deploy a new SAP S/4HANA system and migrate data from the legacy system. The data migration relates only to master and transactional data and does not include any technical data, such as configuration. There is therefore no technical or custom debt brought across from the legacy system. This scenario describes a fresh, new installation of an SAP S/4HANA system and supports two main targets (either the on-premise or cloud edition). This is known as a greenfield approach. The migration to the cloud is denoted by the term SAP S/4HANA Cloud implementation.

Why choose this option?

Choose this option of new implementation or re-implementation if your organization’s strategic goal is to:

• Re-engineer and simplify processes based on the latest digital innovation
• Adopt an on-premise digital core with a long-term vision to integrate with other SAP cloud offerings or migrate to the cloud
• Deploy a strategic investment decision to move to the cloud which is subscription-based (i.e., restructure investment in SAP S/4HANA from capital expenditure (CAPEX) to operational expenditure (OPEX))
• Implement innovative end-to-end business processes with best practice content in mind
• Migrate from non-SAP and legacy third-party systems and retire the old landscape
• Migrate from an SAP ERP system which may:
  • Be highly customized/modified
  • Be an old release and architecture
  • No longer support strategic business needs
  • Not meet system requirements for a technical system conversion
  • Perform an initial data load and resolve historic data issues

Migrate your data with the following SAP S/4HANA tools

The tools and approaches available for cleansing, enriching, and migrating data to a new SAP S/4HANA system are as shown in Figure 2.4. Throughout this book, we will be exploring these tools and this content in greater detail.

Figure 2.4: Tools for migrating to SAP S/4HANA

2.2.3 Landscape transformation

A system landscape transformation is an SAP S/4HANA transition option where an organization (in particular, global organizations with multiple ERP systems) intends to consolidate its regional systems into one single SAP S/4HANA global system.

The prerequisite for this option is that there is a target system available to which data is migrated. This could be a completely new system (in the case of a greenfield approach), or the target system could be created by executing a system conversion of an existing ERP system (in the case of system consolidation).

Why choose this option?

Choose this option if your organization’s strategic goal is to:

• Adopt a value-driven data migration to a new S/4HANA platform—for example, consolidation of multiple systems into one global system
• Adopt a selective data migration—for example, based on legal entities or SAP modules
• Reduce TCO with system and landscape harmonization and consolidation
• Move gradually to SAP S/4HANA innovation
• Implement SAP Central Finance: where an organization has multiple systems, this enables financial documents to be replicated in a new Central Finance system, providing real-time and common reporting capability for the enterprise