As we do custom development as well as in product development the most prominent question concerning S/4HANA is "how do we develop applications in accordance to the S/4 paradigms?". (I am sure every ABAP developer has recently has himself this question, right?)
This question is certainly a valid one, but our customers also have another question going through their heads. They have systems up and running and a lot of data in the systems based on the SAP Business Suite with or without HANA (to make one thing clear: "a lot of data" does not mean big data – common misunderstanding :-)).
So one central question that needs to be answered is:
How do we come from our good old ERP to S/4HANA?
Although simplification is a topic at SAP, the answer is not that simple due to the fact that two deployment options exist and the starting point at customer site can be quite manifold. So let us take a look at the paths that SAP has defined to reach that goal.
As you probably know there are two deployment options for S/4HANA, on premise and the cloud. In this blog we will focus on the "on premise" paths of such a transition
From a 10000 feet perspective there are 3 ways available:
Path 1 - The new implementation
The starting point can be any SAP or non-SAP system. You start with an implementation of S/4HANA from scratch in a greenfield approach. It can be seen as the ultimate bookkeeping of your legacy system (this includes SAP systems) and the risk of cluttering your new system with old "heritage" should be quite low and the probability to benefit of the renewed and simplified processes and new innovations should be quite high. An optional part of that scenario is the transfer of the data from the existing system to the new S/4HANA system. This is usually achieved via a SAP Landscape Transformation (SAP LT) or SAP Data Services (SAP DS).
From my point of view, a very promising way to go that should not be sorted out right from the start for an existing SAP Business Suite. For legacy systems this is anyway the only path they could walk down, if they want to make the move to S/4HANA
Path 2 - The System Conversion
The starting point is an existing Business Suite system that is converted into a S/4HANA system. This means that you transfer your database, your NetWeaver and your application in one step into the new world. There are some preparation steps that have to be executed and probably some adoptions have to be done in order to get the system converted. The preparation is supported by tools like the maintenance planner. The conversion itself is usually a one-step procedure using the Software Update Manager (SUM). This path is a migration-like way to come to S/4 without a complete re-implementation of the business process in the system. Nevertheless, you can cross-check your existing implementation (processes and customizing) with the S/4HANA process and get some benefit out of it
I would guess that this is a quite often used way for existing customers that do not want to make a new implementation from scratch (nevertheless this might make sense as we all know that some systems have rotten over time)
Path 3 - The System Consolidation
Another feasible path is if the starting point are several Business Suite systems that shall be consolidated either partially or completely into a S/4HANA system. This scenario is some kind of mixture of the other two path with a different type of bringing data into the system: in the other two paths it is a 1:1 relation from source to target, now we can have several sources that are consolidated into one target. Again the weapon of choice for the data transfer is the SAP Landscape Transformation. Due to the consolidation part the SAP LT project will certainly be more sophisticated than the one in Path 1.
In my humble opinion another path that allows you to do bookkeeping but on a larger scale than the greenfield approach.
As an outlook: The system conversion option will be presented in more detail in an upcoming blog.