Up until this point, our discussion has revolved mostly around SAP S/4HANA Cloud, public edition, ABAP Cloud, and the SAP S/4HANA Cloud extensibility model. Those rules can be briefly summarized as follows:
- Modifications of SAP Objects are not permitted
- Extensions must be clearly separated from SAP code
- Only released APIs (either local or remote) and extension points are permitted to be used
With SAP S/4HANA Cloud, public edition software updates run automatically and for all customers simultaneously. For customers that utilize SAP S/4HANA Cloud, private edition or SAP S/4HANA, a more traditional (i.e., customer specific) upgrade project is possible since neither is set up to receive automatic software updates in the same way that public edition is. Moreover, the functional scope of both private edition and on-premise is broader than that public edition. These factors contribute to the necessity of allowing some additional use cases for private edition and on-premise that are not permitted in public edition.
Even with that, however, SAP recommends that customers using private edition or an on-premise installation continue to use the ABAP Cloud development model as much as possible. This is particularly true for customers who eventually plan on migrating to public edition. Migrations of extensions built using the ABAP Cloud development model happen smoothly with minimal disruption.
In situations where the ABAP Cloud development model cannot be used, classic extensibility is still available and supported. However, customers should be aware that utilization of these classic extension techniques can present problems. Future evolution for these customers to public edition could potentially be difficult and expensive. Upgrade projects may also wind up being more disruptive than necessary.
As the topics about to be discussed apply equally to both private edition or on-premise situations, going forward, only private edition will be mentioned. If a distinction is necessary, it will be explicitly stated.