1. Copy your SAP ERP system to a sandbox system.

2. Perform a regular conversion on the sandbox system without the downtime-optimized conversion procedure.

3. Define your Customizing settings and perform all SAP Finance-specific IMG steps on your new SAP S/4HANA sandbox system as described in SAP Note 2332030 .

   Your Customizing settings and IMG activities are recorded in Customizing requests that you need to include in your subsequent conversion runs as a customer buffer file.

4. At this point of time, analyze which application tables have a long downtime migration time and can be moved to the uptime with the downtime-optimized conversion procedure. Use the Impact Analysis to verify that the selection does not contain tables with large change volume (> 2,000,000 changes per day).

1. Copy your SAP ERP system to a test system.

2. Perform one to several runs of downtime-optimized conversion on the test system.

3. During the test run, create test data before the downtime, as mentioned in section Test Data for SAP S/4HANA Finance During the Test Run.

4. Include your Customizing requests, which you generated on the sandbox system, in the downtime-optimized conversion procedure with the Customer Transport Integration feature of the Software Update Manager on your test system. This feature is described in the SUM guide in section 4 Planning   Integration of Customer Transports.

5. Only relevant for source systems not yet on SAP HANA database: Enter the path and name of the file containing the selected large tables that should additionally be migrated during uptime.

Perform now an update with the downtime-optimized conversion procedure on your production system including your Customizing requests in the downtime-optimized conversion procedure with the Customer Transport Integration feature of SUM.