Successful migration to SAP S/4HANA

Dealing with custom code in the life sciences industry

Many companies in the life sciences industry face a complex challenge: over the years, or even decades, their SAP ERP systems have been continuously adapted to individual requirements. Strict regulatory requirements, specific production processes and company-specific strategies have meant that standard functions are no longer sufficient. The solution? In-house developments – also known as custom code.

However, these individual adaptations have often accumulated uncontrollably, so that many companies today do not even know exactly how many legacy applications are in their system. However, when switching to SAP S/4HANA, it becomes imperative to deal with these adaptations. Companies are faced with crucial questions:

• Which in-house developments are still necessary?
• Which ones can be shut down or modernised?
• Which should be redeveloped?

Uncertainty about how to deal with existing custom code is causing many companies to hesitate. This blog post shows how to analyse your custom developments, what steps are necessary for a successful custom code transformation and how the SAP Business Technology Platform (BTP) can be used as an extension platform – all in line with the clean core strategy for a future-proof IT landscape.

Our recommended approach to custom code transformation

The transition to SAP S/4HANA requires a careful review of existing custom code, as not all previous enhancements are compatible or still necessary. Key steps in this process are:

• 1. Inventory: identifies all existing custom developments and evaluates their current usefulness.
• 2. Compatibility check: Analyses which custom developments are compatible with SAP S/4HANA and which are not.
• 3. Standard alignment: Checks whether SAP S/4HANA now offers standard functions that were previously covered by custom code.
• 4. Decision on further use: Determines which custom developments should be migrated, redeveloped or made obsolete.

These steps are essential to ensure that business processes continue to run smoothly after the migration. However, the inventory in particular presents life sciences companies with significant challenges. Often, there is no efficient approach – including the use of appropriate tools – for systematically evaluating the existing custom code.

SAP Business Technology Platform (BTP): The solution for custom code transformation?

For in-house developments that prove to be absolutely necessary during the inventory and are not compatible, there are basically two ways of implementing them:

• 1. In-app extensions: Adjustments within the SAP S/4HANA system that are implemented using existing tools and technologies. This approach is also referred to as on-stack.
• 2. Side-by-side extensions: development of standalone applications on SAP BTP that communicate with SAP S/4HANA via interfaces. This method enables a clear separation between standard processes and individual customisations.

The SAP Application Extension Methodology helps you choose the right approach, providing a clear framework and guidelines for companies to extend SAP applications securely and efficiently. At the same time, the integrity and stability of the core system is maintained. Provided they are implemented correctly, both methods are compatible with a clean core strategy without compromising maintainability and updatability.

Our recommendation: start your custom code transformation together with adesso

The first step towards a successful custom code transformation is a thorough analysis of the existing custom code. This is done with the support of best practices and tools such as the Custom Code Migration App. As a result, you will receive a well-founded basis for decision-making, including an estimate of the effort required for your individual transformation.

This forms the basis for targeted planning and successful implementation of the custom code transformation. With our structured approach, life sciences companies can efficiently manage the transition to SAP S/4HANA, reduce future maintenance efforts and continue to benefit from their individual, differentiating business processes.