The migration from classic Asset Accounting (FI-AA) to New Asset Accounting is a mandatory and one of the most complex activities within an SAP S/4HANA system conversion. SAP S/4HANA exclusively uses New Asset Accounting, which is fundamentally different from the classic version. This migration is a significant sub-project that impacts the overall conversion timeline. It requires extensive preparation in the source ERP system, including configuration of new depreciation areas, ensuring data consistency, and executing a dedicated migration cockpit process. The change to real-time data posting between FI-AA and the Universal Journal necessitates thorough testing and reconciliation, adding considerable duration and complexity to the project.

A. The system does NOT use material ledger for actual costing.

While Material Ledger (ML) activation is mandatory in SAP S/4HANA, the process is a largely technical step if actual costing is not in use. It is less complex than the complete overhaul required for Asset Accounting.

C. The customer does NOT use business partners to manage customers and suppliers.

Migrating customers and vendors to the Business Partner (BP) model via Customer-Vendor Integration (CVI) is also a mandatory and significant task. However, it is primarily a master data synchronization and cleansing project, generally considered less complex than the Asset Accounting migration, which involves changes to configuration, transactional posting logic, and deep integration with the General Ledger.

D. The customer uses the accounts approach for parallel accounting.

SAP S/4HANA supports both the ledger approach and the accounts approach for parallel accounting. Therefore, migrating from the accounts approach is not a mandatory step for the conversion, and it does not inherently add to the project's complexity or duration.

1. SAP Help Portal

SAP S/4HANA 2023

Conversion Guide

Chapter 3.2.6.2.1. Asset Accounting (FI-AA): This section details the mandatory preparation and migration steps for Asset Accounting. It states

"You have to migrate your existing asset accounting data to the new data structure in the SAP S/4HANA system... Before you can start the technical conversion... you must perform preparatory steps for Asset Accounting in your source system." This highlights the pre-project effort and complexity.

2. SAP Note 2267965 - S4TWL - Asset Accounting: This official SAP Simplification Item note explicitly states

"Classic Asset Accounting (FI-AA) is not available in SAP S/4HANA

on-premise edition. The new Asset Accounting is the only available solution... A migration from classic to new Asset Accounting is mandatory." The note details the significant functional changes

such as the elimination of delta depreciation areas and the requirement for real-time posting

which are the source of the migration complexity.

3. SAP Help Portal

SAP S/4HANA 2023

Conversion Guide

Chapter 3.2.6.2.10. General Ledger: This section discusses parallel accounting and confirms that customers can continue using the accounts approach

stating

"If you used the accounts approach to parallel accounting in your source system

you can continue to use this approach in your SAP S/4HANA system." This confirms that option D is not a mandatory change.