2.5    Interfaces

So far, this chapter focused on the SAP S/4HANA innovations that affect a single system. If you migrate from an existing SAP ERP system to SAP S/4HANA, this SAP ERP system is usually integrated into a system landscape or has been enhanced with custom or third-party applications. What do you have to take into account in these cases?

First, you should determine how the system has been integrated or enhanced:

• Integration via SAP Process Integration (PI) or SAP Process Orchestration (PO)
  Existing integration that flows through the SAP PI or SAP PO middleware can be kept. SAP S/4HANA is compatible with SAP PI and SAP PO. To integrate new or significantly changed SAP S/4HANA applications, you might have to implement additional integration content.
• Integration via authorized interfaces
  You can continue to use authorized interfaces such as Business Application Programming Interfaces (BAPIs). In SAP S/4HANA, implementations of these interfaces are adapted to the new data model if required. This compatibility, again, refers to traditional application scenarios only.
• Proprietary integration
  If you have implemented custom access options or interfaces, you’ll have to analyze whether you can continue to use them in SAP S/4HANA. When implementing the new data model, SAP took into account compatibility, but some adaptation work may still be required. Chapter 4 describes how to determine this.
• Third-party applications
  If you use third-party applications, you should contact your software provider for more information on their compatibility with SAP S/4HANA.

Depending on the result of this analysis, you may have to include follow-up measures in the planning of your migration project. In summary, the more strictly you followed SAP’s recommendations for the implementation and the more modification-free enhancements or standard interfaces you use, the less follow-up work is required. Chapter 8 and Chapter 13 explain in detail how to integrate SAP S/4HANA into an existing landscape.