14.3    The Most Important Criteria for Your Decision

Based on the examples described in this chapter, let’s now summarize the most important criteria for your decision-making. The four figures in this section refer to two questions. Indicators in each figure provide recommendations, irrespective of your answer to the question. Again, these recommendations are only examples and depend on your specific situation.

The first recommendation (see Figure 14.9) refers to your system requirements.

Figure 14.9    Questions and Evaluations Regarding System Requirements

If your current SAP Business Suite system is a rather old release (lower than SAP ERP 6.0), you’ll have to perform multiple steps when migrating to SAP S/4HANA. First, you’ll have to switch to a release that allows for a system conversion to SAP S/4HANA from a technical perspective. For old releases, a new implementation is the ideal solution, saving you the time and costs required for switching to a newer release. A new implementation would even be faster.

However, certain add-ons and business functions might not be available on the SAP S/4HANA roadmap for now, such as industry solutions. The nonavailability of these functions or add-ons that have not been released yet could delay the implementation of SAP S/4HANA. However, we cannot make specific recommendations in these cases because this limitation applies to all migration scenarios, from new implementations to system conversions.

The second block of questions shown in Figure 14.10 refers to business processes.

Figure 14.10    Questions and Evaluations Regarding Business Processes

If the business processes used so far and the configuration of your existing system meet current business requirements, a system conversion is probably the right solution. For system conversions, the present configuration and the existing dataset are both kept. Refer to the simplification list for information on possible changes relevant to SAP S/4HANA.

If you want to adapt your processes, a new implementation is recommended. In this scenario, you can implement business processes via SAP Best Practices and thus determine the best configuration for your system. Application data is transferred to the new system in a data migration process so that the data corresponds to these new processes.

The third area refers to your custom developments (as shown in Figure 14.11).

Figure 14.11    Questions and Evaluations Regarding Custom Developments

If you wanted to transfer existing code and custom developments (which makes sense if your specific requirements are not yet met by SAP S/4HANA), a system conversion would probably be the better solution. In the case of system conversions, existing custom objects are kept and can be modified, using the custom code migration worklist, for example, to consider changes to data structures in SAP S/4HANA. However, this aspect is not that critical because you can also transfer custom developments in a new implementation. Our experience has shown that these concerns only rarely apply to custom developments.

If you may want to return to the SAP Standard for existing custom developments, you should probably opt for a new implementation first. However, this requirement does not depend on the migration scenario because you can also return to the SAP Standard for custom developments via system conversions. You’ll need to analyze the existing code in detail and schedule the steps for the relevant SAP S/4HANA functions.

The last block of questions (see Figure 14.12) refers to the time to value, that is, to the period of time before the relevant value has been achieved.

Figure 14.12    Questions and Evaluations Regarding Time to Value

How long the migration to SAP S/4HANA takes depends on your individual requirements. Depending on the size and complexity of your existing landscape, a system conversion is often the fastest method if the one-step procedure can be applied. Because your system settings would remain the same, a conversion is usually faster than a new implementation, which may involve a complete redesign of your business processes.

However, SAP Best Practices, in particular the best practices package for SAP S/4HANA, considerably accelerates new implementations. In particular, comprehensive, preconfigured cloud solutions can be available in a few weeks, which is especially interesting if you want to migrate subsidiaries to SAP S/4HANA. With a new implementation, whether the source system is an SAP ERP system or a non-SAP system does not matter because cloud-based systems are always implemented from scratch.

We cannot make general recommendation regarding these risks, which rather depend on the roadmap developed than on the scenario selected. You can select any adaptation speed that meets your current requirements. Whether you transfer a single company code to SAP S/4HANA first or start with SAP S/4HANA Finance is up to you. The only thing that we should mention—as described in this chapter—is that SAP S/4HANA implementations in small steps usually take longer and involve more costs.