Selective Data Transition (SDT) for SAP S/4HANA is a flexible migration approach that combines elements of a new implementation (greenfield) and a system conversion (brownfield). It allows organizations to migrate relevant historical data while redesigning business processes. The two primary approaches within the SDT framework are:

1. Shell Conversion: This involves creating a "shell" of the existing SAP ERP system by copying the repository and customizing configurations into a new S/4HANA system. Master data, open items, and selected historical data are then migrated into this shell, leaving behind obsolete data.

2. Mix and Match: This approach is used for more complex landscape transformations, such as consolidating multiple legacy SAP systems into a single S/4HANA instance or carving out specific organizational units (e.g., a company code) to move to a new system.

A. System Conversion: This is a distinct "brownfield" migration path to SAP S/4HANA, not a sub-approach of Selective Data Transition. It involves a full technical conversion of an existing system.

D. Fit-to-Standard: This is a core methodology within the SAP Activate framework, primarily for new implementations, that focuses on adopting standard business processes rather than a specific data migration technique.

1. SAP White Paper. (2022). Selective Data Transition to SAP S/4HANA. SAP SE. On page 6

the document details the common SDT scenarios: "The shell approach is for customers who want to start fresh from a process perspective but keep their historical data" and "The mix and match approach is for customers who want to consolidate several legacy systems into one SAP S/4HANA system or carve out parts of a system."

2. SAP Activate Roadmap Viewer. (2023). Transition to SAP S/4HANA. In the "Prepare" phase

the task "Define Selective Data Transition Strategy" and its associated accelerators describe the evaluation of different SDT scenarios

including shell creation and system consolidation/carve-out (Mix and Match).

3. Schepes

B.

& Stam

J. (2021). Migrating to SAP S/4HANA. SAP Press. In Chapter 3

Section 3.3.3 "Selective Data Transition

" the authors describe the main approaches

including creating a shell copy and migrating selected data

as well as landscape transformation scenarios like consolidation

which aligns with the "Mix and Match" concept.