The downtime-optimized approach for an SAP S/4HANA conversion using DMO is specifically designed to minimize business downtime by shifting tasks to the uptime phase.

Migration (C): With downtime-optimized DMO, the migration of application data from large tables to the target database (e.g., SAP HANA) is performed during uptime. Database triggers are used to record any changes made in the production system, and these deltas are replicated during the subsequent downtime phase.

Conversion (D): Downtime-optimized Conversion (DoC) allows the content of specific, large application tables to be converted to the new S/4HANA data model during uptime. Similar to the migration, triggers capture ongoing changes for later processing in the downtime phase.

A. Software update: The final software switchover, including the activation of the new S/4HANA software stack and repository, is a core activity that must occur during technical downtime.

B. Main import: The main import phase (e.g., MAINIMPORT), where the bulk of the target release software components and objects are imported and activated, is a critical downtime step.

1. SAP S/4HANA 2023 Conversion Guide

Chapter 3.4.2.2

"Downtime-optimized Approaches". This section explicitly states: "With the downtime-optimized DMO

you can migrate the application data during uptime." and "The downtime-optimized conversion approach allows you to move the data conversion of dedicated tables from downtime to uptime."

2. Software Update Manager 2.0 SP 19 Guide

Section 5.1.3

"Downtime-optimized Approaches". This guide details the procedures for both downtime-optimized DMO and downtime-optimized conversion

confirming that data migration and conversion are the key processes moved to uptime. It contrasts this with standard procedures where these steps occur in downtime.

3. SAP Note 2293733 - Downtime-optimized DMO for SAP S/4HANA conversions. This note describes the procedure and confirms that the migration of application table data (EUCLONEMIGDTRUN phase) is executed during uptime processing.