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Author's profile photo Sachidananda Sahoo

Downtime-Optimized Conversion using SUM for SAP S/4HANA [Brownfield Transition]

Reducing technical downtime is a key element for SAP S/4HANA transition, specifically in a brownfield transition approach. SAP has been working continuously to help the customers to reduce the technical downtime. The Downtime-Optimized DMO method is one such approach which is available to customer to reduce the technical downtime requirement by migrating application tables partially during business uptime. The blog post from Dr. Boris Rubarth will outline further technical details about Downtime-Optimized DMO.

What about the FI/CO/ML/MM-IM conversion downtime requirement during SAP S/4HANA Conversion?

SAP has introduced a methodology called “Downtime-Optimized Conversion” to help the customers in further reducing the technical downtime requirement for FI/CO/ML/MM-IM conversion.

This next generation approach is available for SAP customers starting with SUM 2.0 SP10.

Please refer link

The approach can be used by educated consultants according to SAP Education training ADM329, see link

With the current pandemic impact of COVID-19, many organizations business demands the availability of core SAP systems (SAP ERP) to support ongoing business operations. For these organizations, Downtime Optimized Conversion could be a potential approach for their transition to SAP S/4HANA.

In this blog post ,I will be discussing some High-Level technical details of Downtime-Optimized Conversion using SUM and key points to consider based on my project experiences on Downtime-Optimized Conversion approach.

Introduction: Downtime-Optimized Conversion of SUM

The idea is to “perform the FI/CO/ML/MM-IM conversion of most of the data in uptime of SUM while running production operations in parallel”. During a Downtime-Optimized Conversion, the system runs productively on the old release and at the same time, the Downtime-Optimized Conversion procedure executes the conversion in a separate instance named TEMP instance. Only the partial or remainder of the FI/CO/ML/MM-IM data will be converted during the downtime.

In addition to the above, VBFA and KONV conversion can also be performed in the uptime which is otherwise a separate downtime conversion step in standard SUM procedure. This will help further to reduce the technical downtime.

Below Picture outlines a general comparison between Standard conversion, Downtime-Optimized DMO and Downtime-Optimized Conversion Approach.

The Downtime-Optimized Conversion procedure can be leveraged for non-HANA and SAP HANA databases as source databases.

How Does this work?

For Downtime-Optimized Conversion to work, we need to provide the FI/CO/ML customizing transport created from the previous standard conversion cycle to downtime-optimized conversion cycle as a prerequisite.


Runtime Statistics of Recent Pilot Projects:

The above picture outlines some of the key elements in a  business downtime window for SAP S/4HANA conversion. With FI conversion now being part of the SUM execution in downtime-optimized conversion approach, technical downtime can be significantly reduced.

Refer the columns named Downtime-optimized conversion and the rows highlighted in red. This project is planned to Go-Live in Q4 of 2020.



The above picture outlines reduction in technical downtime that is required for FI/CO/ML/MM-IM conversion .

Refer the rows named Downtime-optimized conversion and the rows highlighted in red. This project went live in 2019.


Key Points to Consider for Downtime Optimized Conversion Projects:

  • Determine the available business downtime vs technical downtime achieved using a standard conversion.
  • Hyperscaler / Transition to cloud from AnyPremise, is currently not supported using Downtime-Optimized Conversion methodology.
  • Considering the use of Downtime-Optimized Conversion for Production; it is important to ensure that adequate non-productive runs of Downtime-Optimized Conversion are practiced.
  • A standard System conversion run is required prior to production cutover; this is mainly required to gather necessary FI/CO/ML customizing transport(s).
  • CTI need to be enabled for Downtime-Optimized Conversion run.
  • SI check and other SAP readiness check related activities need to be completed.
  • A system restart (mini downtime / short downtime) is required for consistent data set. (Ex. Over the weekend before business downtime) with SUM 2.0 SP08. Please note starting SUM 2.0 SP09 mini downtime / short downtime will not be required. Refer SAP note 2975231
  • Data consistency is ensured by two types of DB triggers.
  • Replication triggers record and replay data.
  • Freeze trigger prevent changes: tables become read-only.
  • Replication in uptime phase creates load on PRD system.
  • Mass changes/activities to be avoided during replication (e.g. avoid archiving, no FIN activities).
  • There will be some restrictions “Customizing Freeze” required in the project.
  • There will be some restrictions “Hard Freeze” required after the workbench lock and mini downtime phases in every cycle.
  • Change rate during replication has to be estimated, e.g. based on ST10 data.
  • SUM Impact analysis can be utilized for identifying freeze impact etc.
  • Load verification & Dress Rehearsal cycle to be executed against production system.
  • Downtime simulation environment and isolation activities planning, and timeline should be considered.
  • Below picture illustrates the Downtime-Optimized Conversion cycles that need to be planned for a successful project.

Do you want to sign-up for Downtime-Optimized Conversion to SAP S/4HANA?

If you are looking for further information about how Downtime-Optimized Conversion works in detail and would like to be one of the pilot project participants in the near future, feel free to get in touch with Dr. Boris Rubarth (Product Manager for Software Update Manager (SUM) and Software Logistics Toolset).

If you are SAP’s MaxAttention, SAP’s ActiveAttention and Enterprise Support customer, please reach out to your respective Technical Quality Manager (TQM) or Engagement Architect (EA) or your Account Executive from SAP.

All prerequisites, as well as a detailed description of the registration process to be a pilot customer, is described in the following SAP Note:

2293733 – “Prerequisites and Restrictions of downtime-optimized conversion to SAP S/4HANA” for further information

Refer to Dr. Boris Rubarth existing blog post at


Hope this helps for planning and executing your SAP S/4HANA conversion project.

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      Author's profile photo Rajendra Narikimelli
      Rajendra Narikimelli

      Hi Sachi,

      It is very informative blog and you answered many things at a single place. Your practical experience speaks a ton!

      Looking forward to knowing more from you.



      Author's profile photo Sachidananda Sahoo
      Sachidananda Sahoo
      Blog Post Author

      Thank you Rajendra !!

      Author's profile photo Michael Chien
      Michael Chien

      Hi Sachi,

      This is very informative and helpful for anyone learning DoC, especially the part illustrating differences between HANA/non-HANA source DB.

      Thanks for sharing!


      Author's profile photo Sachidananda Sahoo
      Sachidananda Sahoo
      Blog Post Author

      Hi Michael,


      Thank you for your feedback.




      Author's profile photo Anil Kumar Kunapareddy
      Anil Kumar Kunapareddy

      Very good write up Sachi! Very informative and looking forward to seeing many more informative blogs from you. Thank you for sharing your experience.

      Author's profile photo Sachidananda Sahoo
      Sachidananda Sahoo
      Blog Post Author

      Thank you Anil .

      Author's profile photo Sanjay Bhagat
      Sanjay Bhagat

      Great Article Sachi. Hopefully we can get you to come back for our S/4 conversation when we start the initiative. Looking forward to seeing even more blogs and articles from you on the topic.

      Author's profile photo Sachidananda Sahoo
      Sachidananda Sahoo
      Blog Post Author

      Thank you Sanjay .  Looking forward to work with you as well ?

      Author's profile photo Balaji Rao Gaddam
      Balaji Rao Gaddam

      Great article Sachi. Very comprehensive and informative. I am sure it will be valuable for everyone planning the S/4 HANA journey.



      Author's profile photo Sachidananda Sahoo
      Sachidananda Sahoo
      Blog Post Author

      Thank you Balaji !!