Downtime-Optimized Conversion using SUM for SAP S/4HANA Conversion : InPlace ~ HANA DB vs Any DB

[anandtigadikar]

Motivation & Objective :

As most of the Customers are now looking forward to work aggressively on their S/4HANA Transformation Journey by Converting their SAP ECC systems before they are out of Maintenance on 31st December 2027 , one of the most critical challenge for many of them would be to reduce the SUM Technical Downtime. 

Over a years minimizing downtime is a key element and number# 1 priority for almost all customers while doing SAP S/4HANA Migration, specifically in a brownfield transition approach. To add complexity , customers now even look forward to take an opportunity to migrate from On Premise DC to Cloud ~ Hyperscaler under one major transformation program. 

SAP has been working continuously to help the customers to reduce the technical downtime and complete it in One single maintenance window for such a complex and challenging scenarios. 

To satisfy customer's and on their request SAP came up last year via SUM version SP17 a new GA approach - DMOVE2S4.

Below blog from our Product owner does explain in detail about this new approach

https://community.sap.com/t5/technology-blogs-by-sap/two-major-news-with-sum-2-0-sp-17/ba-p/13548361 

Along with Standard (~ Plain) approach, the Downtime-Optimized DMO ~ doDMO method is one such another approach which is available to customer to reduce the technical downtime requirement by migrating application tables partially during business uptime. The blog post from Boris.Rubarth will outline further technical details about Downtime-Optimized DMO.https://blogs.sap.com/2014/09/08/dmo-downtime-optimization-by-migrating-app-tables-during-uptime-pre...and SAP Note 2547309 - Downtime-optimized DMO with SUM 2.0.

Along with these 2 commonly used ones, SAP has introduced a methodology called “Downtime-Optimized Conversion” to help the customers in further reducing the technical downtime requirement for application tables for core modules like FI/CO/ML/MM-IM conversion.
This next generation approach is available for SAP customers starting with SUM 2.0 SP10 as a Pilot but last year in May'2023 with SUM version 2.0 SP17, it has been made General Available ~ GA for all the customers who can think of converting to S/4HANA and even migrating to Cloud ~ Hyperscaler or RISE . 

Please refer link for more additional details about this approach.

Project requires an educated experts that has taken the respective training ADM329 and successfully passed the Knowledge Assessment ADM329k (requires access to SAP Learning Hub).

Please also refer to this SL Toolset System Maintenance landing page for all the relevant information and for deep dive on different topics - https://support.sap.com/en/tools/software-logistics-tools.html?anchorId=section_18674764 .

Introduction on doC ~ downtime Optimized Conversion:

As compare to other available tools the major advantage of using this tool 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”. Along with that field conversion for KONV and VBFA table is also moved to uptime. 

All these steps are done in downtime for other tools , so this is one big advantage of using doC and below picture speaks itself about it 

Downtime Optimized Conversion ~ doC can be used for both - source as any DB (Non-HANA DB) or InPlace conversion ~ HANA DB

Per my recently completed multiple project experiences of working with different customers, i will share some of the key insights related to Key comparison of phases when Source database is Any DB ~ Non-HANA DB vs HANA DB ~ InPlace conversion. 

Below tabular data is high level information of each of these phases and it's runtime will vary depending upon the size of the tables in your system. 

Downtime/Uptime	SUM Phase Name- HANA DB	SUM Phase Name- AnyDB	Description of the phase
Uptime	RUN_IOC_TOUCH	RUN_SFM_TOUCH SFM ~ Shadow Field Migration	This will handle KONV ~ KOCLU (AnyDB),VBFA and other tables related to SD Migration
Downtime	JOB_KONV_Migration	Delta SFM ~ Shadow Field Migration	This will handle delta KONV ~ KOCLU (AnyDB),VBFA and other tables related to SD Migration
Uptime	SQLRUNTASK_FDCT_TRANSFER_DIRECT	EU_CLONE_CP2STAB_RUN	Copy to Shadow tables happens during this time.
Uptime	Not relevant , as tables are already on HANA	EU_CLONE_MIG_OPTDMO_INI_RUN	Uptime table migration of the relevant tables

In the next blog I will share my experiences on challenges faced by customers across different execution project system cycles ,  how the doC projects should be planned for successful Project completion and which all different teams needs to be involved. 

Thank you for taking time for reading !!

-Anand Tigadikar