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Author's profile photo Boris Rubarth

SUM Prerequisite Check Extended: prepare for the real conversion run


Imagine that you are about to run your very first conversion run on a sandbox system, and you are not sure if any issues will show up. If they do, you will have to solve these before you can continue the conversion run. So each issue has to be solved in sequence, and you do not know what else shows up.


Standard conversion run


As an alternative, the Software Update Manager (SUM), which drives the conversion, offers the Prerequisite Check Extended (since SUM 2.0 SP 08). With this option, you can execute the SUM uptime phases of the conversion to see which issues show up, and you can ignore those issues to get a list of topics to work on afterwards.


Prerequisite Check Extended run

Compared to the conversion run illustration above, the Prerequisite Check Extended uses the same stack.xml provided by the Maintenance Planner.


  • Major issues can be ignored, for example the SI checks (not all)
  • Issue list allows you to work on the topics in parallel afterwards


As a result of the check, SUM will provide a csv file with the respective information and actions in the log directory.


Result log with messages (example)

Check without target SAP HANA DB

Now if your source SAP ECC 6.0 system is not yet based on SAP HANA database (which is not a requirement for the one-step conversion procedure), you will need the target SAP HANA database available to start the real conversion run. The Prerequisite Check Extended even allows to be started if this target SAP HANA DB is not yet available. This will not execute the checks concerning target DB, but at least the other checks are executed.

How to select Prerequisite Check Extended

One of the very first SUM dialogs on Scenario Strategy offers the option.

Note: the Prerequisite Check offered as first option in the list was already available since a while and has a different approach, see HowTo use SUM to check source system prior to System Conversion | SAP Blogs

Additional offering

Now for your first conversion run, you may even stumble in an earlier step of the process. The Maintenance Planner may detect an Add-On as part of your SAP ECC source system for which no version supported on the SAP S/4HANA target release exists. That means that the Maintenance Planner check is red and blocking the conversion planning. So you don’t get the software archives, neither the stack.xml which is required as recipe for SUM. Same applies if Business Functions are blocking the conversion planning in Maintenance Planner.

But we have an offering for this case as well: Maintenance Planner offers you to continue planning and provides software archives as well as a specific check stack file. This check stack file can be used only to run the Prerequisite Check Extended in SUM. If you provide it to SUM, it will directly start this mode, as you are not allowed to run the real conversion yet.



Check stack from Maintenance Planner



  • Not all conversion issues can be ignored during Prerequisite Check Extended
  • Prerequisite Check Extended is not a quick check: it executes the SUM uptime phases of the conversion run and takes the same time as the real conversion. In contrast, the “simple” Prerequisite Check is a quick and non-invasive check, but it only checks the OS level, DB level, and SPAM level requirements
  • At the end of the Prerequisite Check Extended, SUM will not enter downtime but automatically execute a reset. Once this is finished, you store the result list and clean up the procedure. After that, you can start a new run, either Prerequisite Check Extended or the real conversion (in case you already have the real stack.xml provided by Maintenance Planner).
  • Meanwhile (SUM 2.0 SP 09) offers the Prerequisite Check Extended now also for an upgrade of your SAP S/4HANA system
  • A description is part of the SUM guide, see

Hope this feature is helpful for your conversion project.

Kind regards, Boris Rubarth
Product Management SUM, SAP SE

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      Author's profile photo Kundan Gandhi
      Kundan Gandhi

      Hi Boris,

      Thank you so much.

      I have couple questions –

      1. When we are generating stack.xml for Prerequisite Check Extended , do we need to follow any other different procedure, OR is it regular standard procedure?
      2. Will “Prerequisite Check Extended” consider SI-CHECKS also ? Means do we need to fix all errors from SI-CHECKS ?
      3. Will “Prerequisite Check Extended” take same amount of time (uptime runtime), which actual conversion take ?


      If there is no any such dependency, is it possible to merge this output into "Reediness Check report" ?



      Kundan Gandhi

      Author's profile photo Boris Rubarth
      Boris Rubarth
      Blog Post Author

      Hi Kundan,

      thanks for asking.

      1. The stack.xml can be the same file provided by Maintenance Planner that is used for the real conversion run.
      2. Yes, SI checks are executed. Advantage of Prerequisite Check Extended is that you can ignore SI check errors and proceed the uptime processing. In the end, of course, SI checks errors are not allowed for the real conversion run later.
      3. Yes, same amount of time - as already listed in the Remarks section

      I have added text to make points 1) and 2) more clear now.



      Author's profile photo Vamshi Patha
      Vamshi Patha

      Hi Boris,


      is the SUM Prerequisite extended with/without target replacement of chktool that was part of the previous versions of the SUM tool?

      with chktool the summary of the execution was logged in the file CHECKS.TXT which also indicates the requirement for the OS and DB upgrade

      But with the SUM Prerequisite extended tool we cannot find similar information in the PRECHECKEXT_MESSAGES.CSV log file.

      Could you please advise if we need to a different file to get the OS/DB/SPAM requirements or is it implicit that the OS/DB/SPAM versions meet the conversion requirements since it's not called out in the  PRECHECKEXT_MESSAGES.CSV file?


      Thank and Regards,






      Author's profile photo Boris Rubarth
      Boris Rubarth
      Blog Post Author

      Hi Vamshi,

      thanks for asking.

      OS / DB check should be included, but for "Prerequisite Check Extended without target database", the OS / DB check is not included as of now.

      Regards, Boris