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System Conversion to SAP S/4HANA: SUM is the tool

This blog discusses the technical aspects of Software Update Manager (SUM) for a
System Conversion: the transition of an existing SAP ECC system to SAP S/4HANA.

Readers should be familiar with the transition paths to SAP S/4HANA, like described in

New: check out the recordings on system conversion at SAP TechEd 2019:


System Conversion: SUM 2.0 is the tool for the transition to SAP S/4HANA on premise

  • System Conversion transitions an existing SAP ECC system to SAP S/4HANA (on premise)
  • Software Update Manager (SUM) is the tool for this transition

System Conversion: three tasks for SUM to enable Simplification of SAP S/4HANA

  • Software Update: Provide new applications & new tables (as part of the new data model) by providing new software components (like S4CORE) & updating existing software components
  • Database Migration (if source system is based on non-HANA database): migrate existing database content to SAP HANA database (using Database Migration Option DMO of SUM)
  • Data Conversion: conversion of table content to new data model

The data conversion is partly triggered by the SUM, partly an activity after the SUM run (for FIN and ML data: IMG activities).


  • Maintenance Planner has to be used beforehand to check the system and to provide the stack.xml for the SUM (as well as to provide the required software archives)
  • Simplification Item checks have to be executed beforehand, and all issues have to be solved, as the SUM will execute the same checks, and will stop in case of open issues
  • SAP Readiness Check is technically not required before starting the SUM – nevertheless it is highly recommended
  • SAP ECC 6.0 (with or without enhancement packages) is required as source release version
  • Source system has to be Unicode, and an ABAP single stack.

One-step or two: depends on Unicode (UC)

  • General rule:
    • If the source system is already on UC, the transition is a one-step procedure
    • If the source system is not yet on UC, the transition is a two-step procedure
  • Exception
    • For SAP R/3 4.7 and SAP ECC 5.0 Unicode systems: these releases do not include the Customer-Vendor-integration (with Business Partners) that is required for SAP S/4HANA, so a two-step approach is required
  • 😕 Yes, in general DMO may include the UC Conversion – but not for target NW 7.5:
    • NW 7.5 is only UC: no non-UC kernel (and no non-UC export load) available
    • DMO builds up a shadow system for the source system on the new release
    • For non-UC systems, this shadow system has to be non-UC -> not possible for NW 7.5
  • Recommended path for non-UC source systems is discussed below
  • Even if one-step is possible, for business reasons customers may decide to have several steps, as discussed by Frank Wagner (see above)

It is relevant for all target systems based on SAP NetWeaver 7.5 (also for systems part of SAP Business Suite 7 Innovations 2016, like SAP ECC 6.0 EHP 8) that the source system has to be already on Unicode.



One-Step conversion paths

Recommended path for two-step approach: goto 6.17 [this section was edited on march 8th 2016]

  • As discussed above, a two-step approach is required: for all non-UC systems and for R/3 4.7 & SAP ECC 5.0
  • Recommendation:
    • first step to for SAP ECC 6.0 EHP 7 (6.17) with SUM
    • second step later then with SUM (w/ DMO) to SAP S/4HANA
  • Alternative for SAP ECC 6.0 EHP 0…7 on anyDB:
    • You may only do the Unicode Conversion without update & migration (stay on software level)
    • Benefit: no change of business processes, so project effort may be reduce
  • Discussion:
    • Targeting EHP8 not possible, because it is based on 7.50 => requires UC source system


Best regards, Boris Rubarth

Product Manager Software Update Manager, SAP SE

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