Modify your S/4
With Hana and S/4 in particular, a lot is also changing in classic Abap development. The first step is to pay particular attention to which operating form is being discussed. A distinction must be made here between the classic on-premise solution and the cloud solution.
Both forms of operation can be combined with each other. While the classic Abap world is still accessible to SAP users in the on-premise solution, there are definitely some restrictions in the cloud environment.
Almost every SAP user has built various modifications into their SAP system to individualize their processes and set themselves apart from the competition. Whether all these modifications were really necessary remains to be seen. Nevertheless, some of them are certainly valid, otherwise time and money would have been invested in them for a reason.
The requirements change in the cloud environment. With S/4, classic modifications and changes to the code are only possible in the on-premise solution. It can be assumed that future releases will also restrict the way in which we modify today.
No modifications are possible in the cloud environment. This means that the current range of functions must either be returned to the standard or implemented differently before a user can operate their SAP systems in the cloud.
SAP distinguishes here between a key user extension and a managed extension. The key user extension enables minor adjustments to the business process in the form of customer-specific fields and minor code adjustments.
These extensions cannot be compared with today's Abap Workbench, but rather with a very limited tool.
This can be compared to the CRM or Solution Manager interfaces, where new field content can also be created via configuration. Of course, this is not the great freedom that SAP users are used to.
Managed extensibility is available for customizations that cannot be implemented technically. SAP provides users with a development system hosted in the cloud for this purpose.
Extensions can then be implemented on this system. However, this supposed freedom is also restricted. It must be ensured that the implementation does not violate the cloud operating mode.
SAP ensures this by not allowing modifications. Access to SAP objects is also not permitted via a defined interface. This is comparable to the BAPIs released today. A combination of an on-premise solution with a cloud solution on which certain extensions run is conceivable, but requires a certain amount of expertise.
It is certainly conceivable that Fiori applications could be operated in the cloud and therefore be scalable and highly available. At the same time, however, these applications also require gateway services in the ERP backend system.
SAP recommends the development of gateway services for this purpose. Of course, this architecture can only be implemented in a hybrid scenario. Forms are always at the top of the list of customer-specific objects.
SAP solves this in the cloud with a clear commitment to Adobe Lifecycle Designer. All forms or e-mail templates are therefore implemented on the basis of Adobe Forms. Unlike in the traditional world, no print programs are used for data preparation, but NetWeaver Gateway.
OData services, which are used to retrieve and process the relevant information, are therefore the basis for form preparation. It is therefore clear that some things will change fundamentally with S/4.
Migrating an ERP or CRM system from any database to Hana does not yet change the programming model. Nevertheless - in order to benefit from the speed - the customer-specific programs must be checked and adapted if necessary.
With the changeover to S/4, the programming model will change significantly more. OData Services (NetWeaver Gateway), Fiori and SAPUI5 as well as object-oriented developments are the relevant technologies.
Even the forms system, which is often still based on SAPScript or Smartforms, is therefore definitely an old-timer. For a transition towards Hana, IT managers should start analysing modifications early on, bring about standardization and use the new technologies sensibly.