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Our step-by-step guide to your SAP S/4HANA brownfield migration

You are already certain that a Greenfield approach is not suitable for you and are wondering about the steps involved in a conversion (Brownfield Approach) to SAP S/4HANA. This blog article provides you with a guideline on the steps in each phase, following the SAP Activate methodology.

The following diagram roughly illustrates the process of an SAP S/4HANA conversion:


The conversion is divided into several phases: the Discover phase, the Preparation phase consisting of Prepare and Explore, and the Conversion phase with the steps Realize and Deploy. Following this is the phase where the system is already in production: Run.

Discover – Before the actual project start

The Discover phase involves the initial engagement with information about SAP S/4HANA, where the decision to choose this system is made. In this article, I assume that the decision to convert to S/4HANA has already been made and proceed directly to the further steps that should be taken before the actual project begins.

Based on our previous experience, we recommend preparing an SAP S/4HANA project, like any major IT implementation project, carefully in terms of change management. It is advisable to analyze the current situation in your company in two simple steps:

  1. Step: Change-Readiness Check
  2. Step: Stakeholder Interviews

1. Change-Readiness Check

The Change-Readiness Check answers the question of how prepared your company is for an S/4HANA introduction. It is a tool to quickly and with minimal effort gain an overview of various factors relevant to projects.
It serves to classify and prepare the project and can be used as valuable insight into the perspective of relevant employees on an upcoming project and the organisation.

2. Stakeholder Interviews

Systematically engage in brief interviews with stakeholders relevant to the project, especially with critical ones. The goal of stakeholder analysis is to gain a realistic and neutral impression of the project’s starting point and an understanding of the hopes, expectations, and concerns of the interviewees. Involving external consulting partners creates a protected environment. The neutrality and impartiality of the interviewers make it possible for participants to address critical issues and work on them together. This approach allows early identification of conflict issues and the resolution of initial concerns. The interviews generate a broad information base while simultaneously acting as an intervention: relationships are established, initial motivation is sparked, possible backstories are deconstructed, skepticism is leveraged, and a better goal is presented.
The insights gained form the basis for proposals for further measures and concepts related to communication and change, as well as the general conditions of the migration project (schedule, project team composition, project roles, collaboration structures, strategy, etc.). This approach gives stakeholders the opportunity from the beginning to actively contribute to the goals and direction of the project without dominating them.

Business Preparation for Migration to SAP S/4HANA

Before the more technical activities begin in a conversion project, we recommend starting with a brief planning phase to establish the framework and to align the project team both in terms of expertise and project approach.

The following elements set the stage for a successful project:

  • Requirements Analysis: Capture and clarification of requirements, e.g., regarding processes, functionalities, master data, and reporting. Technical requirements may also be relevant, such as integration with existing systems.
  • Process Analysis: Comparison of the current state (Ist) to the desired state (Soll) process.
  • Time and Budget Planning: Definition of the project timeline and a rough estimate of the budget

Technical Preparation for Migration to SAP S/4HANA

In the preparation phase, your current SAP system is enabled to perform the migration to S/4HANA.

Before the more technical activities begin in a conversion project, we recommend starting with a brief planning phase to establish the framework (e.g., scope, timeline, budget, project organisation) and to align the project team both in terms of expertise and project approach.

Afterward, the steps to be carried out within a conversion project begin.

It starts with the examination of system requirements:

  • Is your system Unicode-compatible?
  • Is a Dual Stack Split required?
  • Is a database update necessary?

Following that, the Maintenance Planner (MP), a tool provided by SAP, checks whether the installed components, add-ons, and business functions are compatible with S/4HANA. It also generates the download files needed by the Software Update Manager (SUM) later for the migration.

If all checks are successful, the conversion to SAP S/4HANA is allowed. If the MP does not find a valid migration path (e.g., because an add-on is not S/4HANA certified), it prevents the migration from proceeding.

The subsequent Simplification Item Check identifies crucial steps that must be taken to ensure the system can be technically migrated and that business processes continue to run after the migration. Certain plausibility checks (e.g., in asset accounting) are performed to identify inconsistencies in the system. A detailed log provides information about sources of errors and possible solutions.

blankOur recommendation: We advise conducting the Simplification Item Check as early as possible in the project, as the results can impact effort estimation and project scope. Additionally, any errors should be addressed as early as possible.

The migration of custom code involves analysing developments (Z-programs, extensions, and modifications) and providing information on where the code is not compatible with the new data structures. It is advisable to create a plan early on indicating which adjustments are mandatory or optional.

Moreover, many of our clients have developments in use that are no longer in productive use. In such cases, we recommend evaluating the system over an extended period using the ABAP Call Monitor (SCMON) and removing obsolete coding or programs that are no longer in use.

Furthermore, there are some cross-module activities, such as adjusting authorisations for the use of FIORI, as well as module-specific activities. In logistics, for example, the conversion requires transitioning to Business Partner. Business Partners can be both customers and vendors. The new functionality under S/4HANA is also referred to as Customer-Vendor Integration (CVI) and aims to centrally maintain and manage customer and vendor master data in a single transaction. This provides a unified view of all business partners, making master data maintenance and management more straightforward. The introduction of Business Partners should commence early to prepare the system and users optimally for the integration before the S/4HANA conversion begins.

Technical Conversion to SAP S/4HANA

Once all steps in the preparation phase are completed, the data migration can proceed with the Software Update Manager (SUM). If you do not yet have a HANA database, this is the first step in the conversion phase. Subsequently, the new applications and data structures are installed. In a final step, the migration is carried out, transferring master and transactional data into the new data model.

After the migration has been successfully completed, the system validation begins, ultimately leading to your Go/No-Go decision.

Following this, some post-processing steps are necessary. The new data structures require adjustments to your coding, and certain customization settings in logistics and accounting need to be performed.

Some of the mentioned steps may need to be repeated multiple times within the project, depending on how many test migrations you plan.

Run – Activities After Go-Live

Until the go-live and actual use of the SAP S/4HANA system, project team members are responsible for addressing issues/incidents and handling change requests. Subsequently, this responsibility is handed over to the support organisation, which can be either the internal IT department or an external support provider. Outsourcing support has become a viable option for many companies to address the shortage of skilled IT professionals.

In addition to incident resolution, the optimisation of the system and the processing of change requests fall under the ‘Run’ phase.

PIKON offers SAP Support and Application Management Services. We take care of your 2nd and 3rd-level support. Further information about our services can be found on the support page of our website.


Step-by-step guide to your SAP S/4HANA Conversion


S/4HANA Converion Guide

Learn about the most important aspects of a migration to SAP S/4HANA using the brownfield approach. Following a structured approach based on SAP’s Activate method, we guide you through all project phases in the white paper, from project planning to go-live.

If you would like to learn more about SAP S/4HANA projects, read our other articles on S/4HANA. Alternatively, feel free to contact us directly. We are open to discussing an initial workshop to collaboratively develop your SAP S/4HANA Conversion Roadmap.

Workshop SAP S/4HANA Conversion

Workshop SAP S/4HANA Conversion

Even if the deadline for the introduction of S/4HANA is still far off, we recommend planning your migration scenario early.

Join our workshop to learn how to best approach your SAP S/4HANA conversion project and develop your digital roadmap.

To workshop offer

In addition, we also offer a webinar recording on this topic. The exact content is described in the blog post “Webinar: 5 success factors for your SAP S/4HANA Conversion“.

Webinar “5 success factors for your SAP S/4HANA Conversion“

Webinar “5 success factors for your SAP S/4HANA Conversion“

Best Practice and Lessons Learned from many years of project experience in the mechanical and plant engineering industry
Download the webinar
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About the author
Sarah Leichtweis
Sarah Leichtweis
I am Chief Sales Officer and Head of the ERP department at PIKON Deutschland AG. Together with my team, I implement SAP S/4HANA projects all over the world. In this field of expertise, I focus on the design and implementation of the internal accounting processes with the SAP PS (Project System) and the SAP CO (Controlling) modules.

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