How can I quickly migrate SAP custom code to S/4HANA?

Expert Talk: S/4HANA (powered by it-onlinemagazin)According to recent investment reports from the German SAP User Group (DSAG), up to 80 percent of the companies it surveyed intend to migrate their SAP systems to S/4HANA in the next several years. Certainly a bold endeavor. To minimize internal effort, the recommendation is to eliminate legacy issues – for example ABAP custom code – before the migration takes place.

The following interview between Helge Sanden (Editor in Chief of IT-Onlinemagazin) and Patrick Boch (Product Manager of SAST SOLUTIONS) first appeared on January 10, 2019, in IT-Onlinemagazin.

If you want to migrate to S/4HANA, you must clean up your ABAP code. Scanning ABAP code the conventional way may result in hundreds of thousands of findings and require several thousand days to clean up – longer than the typical professional life of a developer.

I asked Patrick Boch (Product Manager of SAST SOLUTIONS) how the migration time for custom code could be reduced realistically and how these changes to live code can be made without hampering operations.

Mr. Boch, why is it so time consuming to migrate custom code to S/4HANA?

The first challenge that companies face when migrating to S/4HANA is the sheer volume of code. On average, SAP customers have developed 2 million lines of custom code. Enormous effort is involved in shifting it to a new platform. This is in addition to the effort that a company must make to migrate to HANA. Hence, it is highly tempting to integrate the code more or less untested into S/4 HANA.

This leads us to the second challenge: Code that runs on “old” NetWeaver systems doesn’t necessarily run smoothly on S/4 HANA. This means that testing this code is imperative.

Testing code is, in our experience, what takes the most time, whether for a migration or in the “normal” development environment. During S/4 migration projects, companies typically don’t have the time to test the code properly.

What are some approaches to reducing this effort?

It is good advice for companies to test code before migration. In case of the code volume mentioned above, using a code scanner is a good idea. While the effort for this is manageable, a large number of errors are typically uncovered – six-figure results are the rule rather than the exception.

The real challenge is reducing this number of errors in an appropriate manner. There are several topics related to this that we will also cover in our webinar. Here is just one example: In our experience, between 60% and 90% of custom code is typically obsolete. This includes applications developed years ago that have been replaced by SAP standard code or by changes to processes, and programs used once or created as part of development testing and no longer needed. Customers shouldn’t even consider migrating this code to S/4.

What kind of migration timing is doable?

In the case of projects for which the code must be cleaned up, project time is really dependent on the individual customer scenario. You can’t make adequate generalizations here.

However, you can link a well-thought-out project plan with approaches for reducing effort like the retirement of obsolete code I’ve just mentioned. Doing so can result in a reduction of the effort of up to 75%.

What must be accounted for in order to keep operations running at the same time?

As mentioned, the main concern is the vast effort needed for testing. This must be planned in to ensure that the custom code actually works as intended. It is also important that customers not limit themselves to functional testing. The subject of “secure code” should be handled with at least the same level of priority. The security of custom code is simply essential, as systems like S/4 HANA are connected to a large number of other systems and often accessible from the public Internet.

The conventional approach of sophisticated test scenarios has two problems. First, it involves too many resources. Second, such test scenarios will never be able to cover every potential situation.

This is why we’ve taken a different approach. We allow the old code to be “reactivated” at the click of a button if problems arise. The primary advantage of this approach is that it more or less eliminates the testing phase and keeps operations running normally.

Could you tell me in one sentence what you expect the dominating topic to be in the SAP community for the next 12 months?

During the last few months, we’ve seen strong interest among customers for migrating their systems to S/4 HANA. While other indications point to the fact that that moving to the cloud will be one of the biggest, if not the biggest, topic in the SAP environment in the medium term, most customers will be looking at S/4 migration in the next 12 months.

Thank you for the interview.

Helge Sanden, Editor in Chief of IT-Onlinemagazin, asked the questions.


Patrick Boch, Product Manager SAST SOLUTIONS

Helge Sanden IT-Onlinemagazin
Helge Sanden, Editor in Chief of IT-Onlinemagazin


Related articles in the SAST BLOG

The State of SAP Security 2018: Between platform security, authorization management and S/4 HANA migration.

Are you really that attached to your ABAP security flaws, or is it time to say goodbye?