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Lesson 1 of 5

SUM overview: scenarios, versions and inputs

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The Software Update Manager (SUM) is SAP's tool for changing the software level of an ABAP-based system. It applies support package stacks, installs enhancement packages, performs release upgrades and, for SAP ERP 6.0 systems, performs the technical system conversion to SAP S/4HANA. With its Database Migration Option (DMO) it can also move the database to SAP HANA in the same run. Whatever the scenario, SUM is the one tool that touches the repository, the kernel and the data structures together, which is why its run defines the technical downtime of most SAP maintenance events.

SUM is delivered as part of the Software Logistics Toolset (SL Toolset) on the SAP Support Portal and is patched often. SAP publishes it in two lines. SUM 2.0 is for targets based on SAP_BASIS 7.50 and higher, which includes every SAP S/4HANA release, so every ERP-to-S/4HANA conversion uses SUM 2.0. SUM 1.1 covers dual-stack or Java sources and ABAP targets on SAP_BASIS 7.40 or lower. As of October 2026 SAP's SUM page lists SUM 2.0 SP 27 (central SAP Note 3705604) and SUM 1.1 SP 05; always download the latest support package and read its central SAP Note before a project starts, because the note lists restrictions that change between support packages.

Which SUM line to use: every target on SAP_BASIS 7.50 or higher, and so every SAP S/4HANA conversion, uses SUM 2.0.
The Sign-Off Table · thesignofftable.com/academy/sap-bas-301
ScenarioWhat changesTypical example
UpdateSupport packages or a Feature Package Stack within the same releaseSAP S/4HANA 2025 FPS01 to a later FPS
UpgradeMove to a new major release or enhancement packageSAP S/4HANA 2023 to 2025; ECC EHP 7 to EHP 8
System conversionSAP ERP 6.0 becomes SAP S/4HANA: new software, new data model, data convertedContoso's ECC 6.0 EHP 8 to SAP S/4HANA 2025
DMODatabase migrated to SAP HANA (or another target) combined with the software change, or migration onlyA non-HANA ECC database moved to SAP HANA during conversion
The main SUM scenarios. DMO is an option of SUM, not a separate tool.
The Sign-Off Table · thesignofftable.com/academy/sap-bas-301

Where SUM sits in a conversion

SAP's Conversion Guide for SAP S/4HANA 2025 splits a conversion into a prepare phase and a realize phase. Preparation uses the SAP Readiness Check, the Maintenance Planner, the Simplification Item Check (report /SDF/RC_START_CHECK) and custom code analysis. Only then does SUM run. Inside SUM, the conversion is a one-step procedure for supported start releases: optional database migration with DMO, installation of the SAP S/4HANA software, and conversion of data into the new structures. Application follow-up steps, such as the finance data migration described in SAP Note 2332030, come after the technical run.

  1. Readiness CheckPlanning view: simplification items, add-ons, custom code, sizing
  2. Maintenance PlannerChecks add-ons, business functions and industry solutions; generates stack.xml and download basket
  3. SI-CheckMandatory consistency checks; SUM runs them again
  4. Custom code analysisFinds code that conflicts with simplifications
  5. SUM runDMO if needed, software update, data conversion
  6. Follow-upFinance migration, SPAU, custom code fixes, Fiori and output setup
SUM is the realize step. Everything before it decides whether the run can succeed.
The Sign-Off Table · thesignofftable.com/academy/sap-bas-301

The inputs SUM needs

InputWhy it matters
Stack configuration file (stack.xml) from the Maintenance PlannerDefines the target software levels and add-ons. The conversion guide calls running the Maintenance Planner mandatory because SUM requires the stack file; generating it for a conversion requires an SAP S/4HANA license.
Download directory with the archives from the Maintenance Planner basketSupport packages, add-ons, kernel files for the target database and the SAP HANA client for DMO.
The latest SUM 2.0 archive and its central noteFixes and restrictions change with every SUM support package.
Prerequisites met in the sourceUnicode, AS ABAP only (dual-stack systems must be split first), supported start release per the 2025 restriction note, SI-Check errors resolved.
Transports collected in earlier runsChanges that can only be made after conversion are collected in transport requests and handed to SUM for later runs.
Migration key and target database details (DMO only)Needed when the database type changes.

What has to be ready before a SUM run starts.

Under RISE, SAP ECS runs SUM, but Sam owns what goes in and what comes out: reviewed inputs before the run, a handover to testing after it.
The Sign-Off Table · thesignofftable.com/academy/sap-bas-301

What would you do?

Two weeks before Contoso's first sandbox conversion, the Maintenance Planner refuses to produce a stack file because an add-on in ED1 has no released conversion path. Kenji suggests starting SUM anyway with a stack file from another project. What should Sam do?

Key points
  • SUM performs updates, upgrades and ERP-to-S/4HANA conversions; DMO adds a database migration to the same run.
  • Every S/4HANA conversion uses SUM 2.0; use the latest support package and read its central note.
  • SUM needs the Maintenance Planner stack.xml, the downloaded archives, met prerequisites and, for DMO, target database details.
  • Under RISE, SAP ECS executes the technical conversion as a contracted service; the customer still owns inputs, checkpoints and testing.

Check your understanding · not graded

Lesson check

  1. 1. Which SUM line is used for every conversion from SAP ERP 6.0 to SAP S/4HANA?

  2. 2. What does the Maintenance Planner produce that SUM requires for a conversion?

  3. 3. Which of these must be true of the source system before a one-step conversion to SAP S/4HANA 2025?

  4. 4. Under RISE, who typically executes the SUM run for Contoso's technical conversion?