Choosing the right service for S/4HANA transition in near zero downtime
If your company has already decided on transitioning to S/4HANA with the near zero downtime approach, you might be looking now for the right tools to execute it. And this is not an easy choice!
When I started to collect information regarding downtime optimization options, I realized that the information available is very confusing. Therefore, I decided to prepare a clear and comprehensive comparison of SAP tools and services which are a part of the standard Software Update Managed (SUM) and are offered to minimize downtime during ECC to S/4HANA transitions. I will also have a look at Datavard’s near zero downtime solution and compare it on two most common scenarios:
- Scenario A: Standard System Conversion known as the “Brownfield Conversion”
- Scenario B: Cloud migration requiring data selection or transformation
Product comparison
SAP ZDO: This service known as the “Zero Downtime Option” and is a part of the standard software manager. However, for now it is delivered only as a service-based pilot projects run only by SAP (2707731)
SAP nZDM: nZDM stands for “near-Zero Downtime Maintenance” and is also a part of the standard software update manager. SAP nZDM has two components for downtime minimalization:
- Downtime optimized DMO – used for optimization of data migration phase. This component can be used also by SAP partners.
- Downtime optimized conversion – used for optimization update/convert phase. Using this components is available only for SAP service-based projects (2293733)
Datavard NZDT: Datavard NZDT is delivered as a tailored-service based project using the Datavard Transformation Suite
SCENARIO A: Standard System Conversion known as the “Brownfield Conversion”
- Source: ECC6.0 EHP4 on premise
- Target: S/4HANA 1909 FPS01 on premise
- Data selection: No
- Data Transformation: No
- Maximum downtime: 48 hours
Key point 1: Feasibility
SAP ZDO | SAP nZDM | Datavard NZDT | |
Does the solution/service support in general ECC to S/4HANA NZDT? | NO* | YES | YES |
Does the solution/service support all types of source database? | N/A | NO** | YES |
Does the solution/service support Non-Unicode source? | N/A | NO*** | YES |
*Based on the note 2707731 SAP ZDO is designed for updating releases of SAP S/4HANA systems only (e.g. from SAP S/4HANA 1809 FPS 01 to SAP S/4HANA 1909 FPS 01)
**Based on the note 2547309, SAP nZDM is supported only on DBs – Oracle (at least on Oracle 12)/DB6/MS SQL (with SUM 2.0 SP 07 and higher)/IBM Db2 for z/OS (with SUM 2.0 SP 08 and higher)
***Based on the note 2547309, Non-Unicode start releases are not supported using SAP nZDM
Key point 2: Downtime optimization
SAP ZDO | SAP nZDM | Datavard NZDT | |
Does the solution/service support uptime data migration without any limitation? | N/A | NO* | YES |
*Based on the note 2547309 there are multiple limitations within SAP nZDM when it comes to including various SAP tables into the uptime migration, which is the main way how to achieve optimized downtime. For example, the largest tables are not possible to include (e.g. KONV, VBFA, BSEG(RFBLG), CDPOS(CDCLS), BSAK,BSIK, …)
Conclusion for Scenario A
Based on the evaluation above my recommendation is the following:
For small-sized ECC systems (1-3TB) I would recommend to use a SAP nZDM – Downtime optimized DMO option. Due to a smaller system size it is very likely that “Downtime optimized conversion” is not required. Datavard NZDT or other 3rd party/SAP customer tailored NZDT solution do not bring the additional value on top of SAP built-in solution.
For medium-sized ECC systems (3-5TB) Using SAP nZDM for such system size may be questionable. The major limitation of the SAP service is in the uptime data migration (described in Key point 2: Downtime optimization), which means downtime requirement of 48 hours may not be met. Depending on the distribution of data within the system – if the biggest tables in the ECC system are tables which are subject to S/4HANA postprocessing (e.g. MKPF, MSEG, KONV, BSEG(RFBG), LIPS, VBAK, VBAP,…) – it is very likely that “Downtime optimized conversion” service will be required. For addition, Datavard NZDT may reduce the downtime comparing to SAP nZDM due to unlimited NZDT settings.
For large-sized ECC systems (>5 TB) The limitation in the uptime data migration (described in Key point 2: Downtime optimization) seems to be the major barrier to minimize system downtime. My recommendation is to use Datavard NZDT or other 3rd party/SAP customer tailored NZDT solution approach where the uptime migration can be tailored to achieve 48 hours downtime.
SCENARIO B: Cloud migration requiring data selection or transformation
- Source: ECC6.0 EHP4 on premise
- Target: S/4HANA 1909 FPS01 in the cloud cloud
- Data selection: Yes (e.g. carve-out only subset Company Code)
- Data Transformation: Yes
- Maximum downtime: 48 hours
Key point 1: Feasibility
SAP ZDO | SAP nZDM | Datavard NZDT | |
Does the solution/service support in general ECC to S/4HANA NZDT? | NO* | YES | YES |
Does the solution/service support cloud migration using NZDT? | N/A | NO** | YES |
Does the solution/service support data selection and transformation? | N/A | NO*** | YES |
*Based on the note 2707731 SAP ZDO is designed for updating releases of SAP S/4HANA systems only (e.g. from SAP S/4HANA 1809 FPS 01 to SAP S/4HANA 1909 FPS 01)
**Based on the note 2547309 and 2293733 downtime-optimized DMO and conversion are not allowed to use for scenario “DMO with System Move”, which means SAP nZDM cannot be used for NZDT cloud migration.
***Based on the note 2293733 SAP nZDM works only with System Conversion approach, which is complete technical in-place conversion of ECC into S/4HANA system without possibility to select or transform data during S/4HANA conversion
Conclusion for Scenario B
In case of the ECC to S/4HANA NZDT cloud migration, or a requirement to include selection or transformation, it is only feasible to use Datavard NZDT or other 3rd party/SAP customer NZDT tailored service.
Note: Comparison and recommendations are created based on the available SAP blogs/OSS notes and my personal experience as Solution architect working on multiple NZDT transformation projects.