10.3    Technical Conversion

Technical conversion to SAP S/4HANA involves a sequence of activities to be performed in the preparation phase and the realization phase. Figure 10.6 provides an overview of the tools, phases, and activities involved in the technical conversion process.

Figure 10.6    Technical Conversion Path

10.3.1    Technical Considerations

The migration strategy analysis suggested in this chapter defines the technical considerations that are taken into account. In this section, we explain the following considerations suggested for an SAP S/4HANA migration:

• Business functions
  • Switch framework composition on the source system determining factor of the system readiness to migrate
  • Significant increase of computability in release 1610 FPS01
• Industry solutions and add-ons
  • Industry solutions and add-ons installing in the system required to be compatible with SAP S/4HANA
  • Currently, 24 add-ons supported in release 1610 against 31 in release 1511
  • Verify with SAP on any conflicts
• Impact of process simplifications
  • The system against the SAP S/4HANA simplifications
  • Level of usage of the conflicting business processes in source
  • On average, 30–40 simplifications
  • Effort and complexity of the redesign
• Infrastructure
  • Age of the system and applications architecture
  • Cost implications and hardware compatibility
  • SAP ERP release, enhancement package, and database platform
  • In transition to SAP S/4HANA, the source system not required to be already on SAP HANA database
  • Bolt-on systems integrated and their compatibility
• Custom code and user experience (UX)
  • Level of customization done and percentage of usage
  • Efficiency of the code and effort involved in the corrections
  • System performance and amount of SAP HANA optimization required
  • Compatibility of older SAP Fiori apps
• Data
  • Data model conflicts
  • Customer and vendor mapping
  • Size of the master and transactional data

10.3.2    The Technical Conversion Preparation Phase

The prepare phase concerns the activities that should be completed before you execute the Software Update Manager (SUM) tool. This phase consists of four activities: archive data, fine-tuning, data model impact, and system requirements, as described in the next subsections.

Archive Data

The volume size of your system is significantly reduced based on the new SAP S/4HANA data design. It’s recommended to plan and implement an effective smart data conversion strategy and a future data archiving strategy to better manage system performance and cost management.

If you’re converting your SAP ERP legacy systems into SAP S/4HANA, reduce your data footprint in the legacy system before starting the conversion, which prevents you from bringing unwanted old data and improves the process conversion performance overall.

Fine-Tune Your Reporting Strategy

The strategy under review should take into consideration not only structured data from your transactional system but all relevant sources of nontransactional data or unstructured data. This also includes the amount of data that your organization needs to process active or life data reports (hot data), mid-term historical data (warm data), and long-term historical data (cold data).

Note

Reporting strategies are available for your review in Chapter 9.

Data Model Impact

Analyze the impact on your current data model, and expand the analysis to include unstructured data. A clear business strategy to define current reporting needs and future business tendencies allows you to design a stronger data model. We suggest you complete the following activities to align your data model:

• Realign capability thread engagements to vision statements.
• Revisit design decisions due to technology limitations.
• Retrofit test banks and test repositories.

System Requirements

You need to understand the state of the current system and gather information on the target SAP S/4HANA product (e.g., SAP S/4HANA 1709), such as system sizing requirements and the latest SUM version.

As a prerequisite for the conversion, the source system must be a Unicode system. Your system has to be an SAP NetWeaver Application Server for ABAP (SAP NetWeaver AS ABAP) system, the dual stack systems SAP NetWeaver AS ABAP and SAP NetWeaver AS Java aren’t supported for the conversion. If you want to understand more details of the dual-stack split process, refer to the following two SAP Notes: 1686144 and 1655335.

You’ll need to consider all impacts with the SAP S/4HANA conversion because it’s possible that you’ll need to adapt further systems in your system landscape. If you have the following SAP NetWeaver Java instances, such as Adobe Document Services, ES Repository, or AEX, they need to be running on SAP NetWeaver 7.3 EH1 or in a higher version before being converted into an SAP S/4HANA system.

If your current system has an existing SAP Fiori frontend server, you can use it for a new SAP S/4HANA system. The existing apps need to be configured to run against a new SAP S/4HANA system.

10.3.3    Risks and Lessons Learned

The following is a list of risks and experiences after several successful SAP S/4HANA migrations:

• Competing or conflicting priorities
  Competing or conflicting priorities can increase risk, reduce business value achieved, and delay project timelines. Prioritization of business and technology initiatives into a combined road map helps reduce resource congestion and set clear objectives.
• Path to competency
  Enabling and building SAP HANA-related competency in areas such as development, system administration, and support will be critical. There are several avenues available to clients such as classroom training, leveraging partnerships, professional services, and hands-on experience that will enable a path to building SAP HANA competency.
• Infrastructure readiness
  Activities related to SAP HANA appliance configuration and design, data center readiness, physical appliance setup, planning, and installs will be important to meet the project timelines. We also recommend enabling a N+1 landscape for future projects. Meeting project milestones and completing system build activities as planned is critical to the success of the project.
• Business continuity and downtime planning
  During the project, and especially during production cutover, there will be a need for system downtime for migration activities, so it’s important that you work closely with the business and users to coordinate the timing and minimize impact to business operations.
• Platform stability and business validation
  Along with high availability, failover, disaster recovery, and system-hardening activities, it’s crucial that streamlined business validation of critical scenarios and involvement from stakeholders is made a priority to identify issues and a resolution path as early as possible.
• Change impact
  SAP Business Suite powered by SAP HANA upgrade can potentially introduce changes to transactions, processes, and UX. Change impact and training efforts should be included.
• New technology can mean new challenges
  SAP HANA is new technology, and new technology can mean encountering issues for the first time. It’s still important to allow time for issue resolution and maintain close contact with SAP for issue resolution.
• Limit migration downtime
  Based on our past experiences, we recommend provisioning a direct, strong network connection between source and target system. Run data management tools to clean unwanted data from sources to reduce the footprint, and then conduct a dry run on the production size database to improve the approximation of export and import time.