In the earlier blogs, I’ve elaborated on what selective data transition is, the process involved, and the two approaches to selective data transition. If you’ve not read them yet, you can find them here!

Well, this writing entails providing a comparison between both approaches.

Hope you guessed them right, yes, it’s a comparison between the Shell Approach and the Mix & Match approach. Let’s begin with the definitions,

What’s Shell Conversion Approach?

This option removes all data from your existing SAP ERP system, leaving the system empty with the settings. System conversion is used to convert the system to your SAP S/4HANA. Because there is no data in the configuration, you may make any necessary adjustments to your new SAP S/4HANA system.

Post the completion of the necessary improvements, the data is then migrated to the S/4HANA system. If you requested any modifications in the current system, the historical data will be altered during the transfer to the new SAP S/4HANA. Data updates that migrate at the table level will be carried out in dedicated afterburner scripts.

What’s Mix & Match Approach?

If the extent of new business processes in S/4HANA or enhancements in ECC 6.0 makes the legacy system a less-than-appealing starting point, the Mix and Match option avoids the Shell Conversion stage in favor of starting with a clean S/4HANA system.

This may appear to be a “New Implementation” approach, and it is, but with significant acceleration.  A variety of reference systems can help to accelerate business process setup. These include the older ECC 6.0 system, SAP Model Company systems, and Best Practice information. The point is that expertise and a reference system drive business process design.

Now you can very well understand why Selective Data Transition is called the Bluefield approach because the shell method is inclined towards the System Conversion (Brownfield) and mix & match is inclined towards New Implementation (Greenfield).

Look into the image below to have a better understanding. Time to brief out about both the approaches;

Shell Approach:

Shell Approach as a solution to transform to S/4HANA from your old SAP ERP, focuses to offer you greater flexibility for adjustments than a system conversion. The steps involved in the process are:

We begin by creating a shell of your present SAP ERP solution, leaving you with an empty system containing only the configuration and no transaction or master data.

  1. Configuration signifies that this system only contains customization and repository items. This system will be converted to SAP S/4HANA utilizing the standard system conversion procedure.
  2. Because this system has no data, you can make any modifications to the setup of your new empty SAP S/4HANA system that you require.
  3. Now you can duplicate the current system.
  4. The data migration will be the following stage. For those areas where no major changes were made, it will be easy to move previous data and update it on the fly to the new SAP S/4HANA architecture.
  5. Since in these areas, data will be transferred at the table level, and the fly modifications required for SAP S/4HANA will be carried out in specific after burner programs – these will be the same or comparable to those carried out during a standard SAP S/4HANA system conversion.
  6. Other migration techniques will be utilized for those sections that require fundamental modifications, which populate the data in a secure manner via the system interfaces – consequently, no historic records may be shared for this data.

MIX & MATCH Approach:

While the Shell Approach allows you to make a system conversion approach more flexible, the Mix and Match Approach allows you to enhance a Greenfield Approach by retaining and safeguarding those portions of your setup that do not require any changes. This strategy is utilized considerably less frequently than a Shell Conversion Approach.

The main concept behind the mix-and-match scenario is, to begin with a greenfield approach while retaining your existing solution for certain solution areas where your present SAP ERP solution has proven to satisfy both your current and future expectations.

Since the solution majorly focuses on retaining some parts of the current solution, the first step in the process will be to identify and remove the bugs and fixes of the existing solution.

Missing this step would ruin your entire transition to S/4HANA since incomplete and siloed operations will affect the entire migration. Post the identification of the solution areas you are left with two options:

  1. Approach experienced consultants to manually add the configurations to the new SAP S/4HANA solutions
  2. Utilize the available automation tools to aid your transition to SAP S/4HANA.

When you attain a minor or no change state in your transition from SAP ERP to SAP S/4HANA you can transport your custom data directly and rework it manually in order to customize the target system.

In case within the process you explore major changes it’s time to shift to the Shell Conversion approach.

In most circumstances, the Mix & Match technique requires no specific tooling and simply knowledgeable advisors. As a result, clients that require this strategy will not contact DMLT, and we have no idea how frequently this approach is really used.

Hope this blog was helpful.

To conclude with; if you opt for process re-engineering in some areas opt for shell conversion and if there are extensive changes choose Mix & Match approach. If you wish to gain more details on how the selective data transition works, get in touch with our expertise!