A practical guide to SAP ECC to S4HANA migration: steps, strategies, common challenges, costs, and how to pick the right partner before 2027.
SAP has been the industry standard for a lot of ERP tasks for enterprises, with many companies having used SAP ECC for the majority of the last decade.
But from an operational standpoint, when it comes to making your data more flexible, having more accurate, real-time data, S4HANA is an option most enterprises are looking at.
S4HANA comes with easier integrations, better automation, and faster processing, which can seem tempting! But, there is ONE overbearing question!
Is migrating from SAP ECC to S4HANA worth the expenditure?
So to help you make the right decision for your company, we’ll cover the steps and challenges (along with fixes) for SAP ECC to S4HANA migration.
Well, while many people might say migrating to S4HANA is for automation, that is only one factor.
The reality is that just as Java-based phones or older Android models got outdated, SAP ECC is going to keep getting more inconvenient based on how enterprise apps are evolving.
But more than that, it falls down to these criteria:
Just like with any migration project, moving from SAP ECC to S/4HANA comes with systematic steps.
And as any reasonable project manager would inform you, it requires a sound framework and selecting the migration model that suits you and your company best.
But also to help you feel reassured, over 59% of companies are already fully or partially live on the advanced S/4HANA platform - meaning it definitely is the right step to make.
The reality is that for a phased-out but initial hybrid route, when it comes to SAP ECC to S/4HANA migration is a great place to start.
Although many companies are moving towards S/4HANA, some user reddit claim that the number of actual users more close to only 39% of companies in Germany that have officially licensed the S/4HANA platform to their ecosystem (this after nearly 10 years in the market!)
When migrating from SAP ECC to S/4HANA, there is no single path that guarantees success, so picking the right strategy upfront really matters.
Committing to a strategy is very important. But you HAVE to make sure it matches your technical debt and business goals.
By doing this, you prevent the costly changes that happen when teams realize, too late!
The three main ways to do it include:
Scope creep is the single biggest driver of budget overruns in S/4HANA projects.
Avoid this! Stopping the irreversible scope creep before the build begins keeps units from constantly requesting new customizations later (this is what turns 12-month projects into 24-month projects!)
When migrating from SAP ECC to S/4HANA, you need to make sure to:
Cleaning data first protects the real-time analytics you are migrating for in the first place.
Why? Well, carrying duplicated or unstructured records into a Business Partner framework exposes flaws that quietly fudge reporting and cause reconciliation issues.
Before migrating from SAP ECC to S/4HANA, you will need to make sure that your data is cleaned and prepared for migration, the benefits of HANA will be lost due to your bad data. It is important that you:
Odds are high that your SAP ECC was coded 15 to 20 years ago by consultants who have since left their jobs and usually do not leave any documentation.
For the move from SAP ECC to S/4HANA, the fixing of the custom code will be one of the technical aspects you'll need to tackle.
This is because the tables in the database have been fundamentally altered. But when doing this, here are some steps to take:
During your SAP ECC to S/4HANA migration, the preparation of infrastructure determines how your demanding new HANA environment can be hosted
Your HANA database environment requires lots of memory, and thus, can become quite expensive! Which is why your choice of hosting determines performance and TCO.
This is precisely why the primary steps you need to focus on should be:
The moment your business actually moves onto a new platform like S/4HANA, for firms running 24/7 operations, every extra hour offline means lost revenue and missed SLAs!
Making use of downtime-optimized tooling is what turns a multi-day outage into a manageable weekend window later on. But to do this, you’ll likely need an SAP specialist or SAP consultants for tight control over downtime, with these key steps:
Defects are inevitable, and catching them across integration and user acceptance testing, plus a full dress rehearsal, is what gives your governance board confidence during a SAP ECC to S/4HANA migration.
This will help you and your team make a clean go-live decision without too much concern. Typical ways you should test and validate are:
The move from SAP GUI to Fiori is a completely different ballgame! So, structured training, a gradual rollout, and a staffed hypercare period are what protect productivity.
More importantly, it helps the team and business actually realize the value of the move. This can be done by:
Legacy systems often carry decades of duplicated, incomplete, or inconsistent master data.
These issues tend to stay hidden during early mock loads and only surface during User Acceptance Testing, when the full production copy exposes missing records and reconciliation mismatches.
To tackle this, teams treat data remediation as a business-led initiative that starts months early, using tools like SAP Information Steward for profiling and a validated “Golden Data Set” for testing.
Teams often demand that legacy code written 15 years ago be preserved at all costs (which is counterintuitive to removing your technical debt!)
To tackle this, teams need to have a strict fit-to-standard protocol.
Meaning, only truly critical logic is built side-by-side as extensions on SAP BTP, with automated remediation tools handling the routine code conversion accurately.
Resistance usually stems from change fatigue and the learning curve of the new Fiori interface.
This, alongside skilled teams forced into unfamiliar workflows without ACTUAL NEED, causes users to grow frustrated and can cause a drop in productivity.
To deal with this, change management is prioritized alongside technical work by introducing a few high-value Fiori apps at a time, keeping SAP GUI as a safety net.
But more so, building a network of skilled, change-positive users to drive peer-to-peer usage can also help.
Your ERP does not work by itself. Your ERP is always connected to CRM platforms, logistics tools, and manufacturing systems.
But the challenge is bringing all of these to align with your new tool - in fact, 49% of organizations mention this as an issue!
In order to handle this, only connect the critical interfaces for a stable go-live.
And then, defer broader rationalization on the SAP Integration Suite and BTP to a later optimization phase or gradually in phases.
The move to S4HANA can be quite challenging and potentially cause some downtime.
The traditional method would put the productive environment out of work completely! And, for companies that provide 24-hour services, even a day or two would have a huge impact on financial performance.
To deal with such an issue, a downtime-optimized approach is used to reduce the downtime period.
With the year 2027 drawing closer, a lack of specialized talent raises costs in the form of consulting fees, while scope creep turns one-year projects into over two years and subtly reduces budgets.
For a good management of this situation, teams must collaborate with a strict, immutable scope from the beginning, and also with firms with a fixed cost model (or fixed-bid model).
Also, ideally, teams relying on automated testing and AI-based remediation reduce the number of billable hours for development.
Migrating to S/4HANA involves a huge cost expenditure, so when creating a business case for the project, it is essential to know what determines the price.
The success of your migration from SAP ECC to S/4HANA is closely tied to the partner you choose, and with the 2027 deadline creating a real bottleneck.
In fact, 76% of organizations say that a proven track record is a fundamental requirement!
Which is why working with the right SAP Migration Partner partner like Entrans, makes sense.
Having worked with over 100+ trusted enterprises, our flexible fixed-bit plans help make sure that you migrate to S/4HANA with an actual ROI on your investment.
Want to know what this could be like for you? Book a free consultation call for a quote!
Greenfield is preferable for a group eager to get rid of legacy processes and start anew, while Brownfield will work out well for more established firms that require preserving historical information. There is also Bluefield (Hybrid), which allows you to have a greenfield route while keeping the needed data.
This depends completely on the project's scale and the amount of custom code, but Brownfield conversion may typically last from 12 up to 24 months. That said, it is possible to perform smaller projects focused on finances within 10 weeks after proper preparation of the landscape.
Yes, but it is not recommended! This is due to the technical debt and the inability to update in the cloud in the future. You'd rather discard unimportant legacy and develop critical functions separately in the SAP BTP environment.
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