In our first blog, we explained what SAP’s clean core really means and why it matters. When SAP launched its “clean core” strategy in 2021, it seemed like the ultimate fix for decades of customization chaos. Three years later, that vision hasn’t quite materialized.
You probably recognize the signs: You’ve moved to SAP S/4HANA. You’ve embraced clean core in theory. But custom code is creeping back in. Governance is slipping. Business users demand quick fixes. And your system feels familiar, not in a good way.
Last month, a client running S/4 for over two years told me: “We still talk about keeping the core clean, but honestly? It feels like we’re just building a new version of the same old monster.”
Here’s why that keeps happening , and what it reveals about how your SAP landscape is really being managed.
The 5 patterns where Clean Core falls apart
1. You never actually cleaned house
Most companies didn’t start clean, they migrated everything. Old custom code, abandoned enhancements, Z-tables nobody owns anymore. One client had over 30,000 custom objects with no real idea which ones were still active.
What we see in practice: Teams retrofit old customizations instead of questioning whether they’re still needed. A manufacturing client spent 6 months rebuilding a custom scheduling algorithm on BTP, only to discover the business had switched to a different planning approach two years earlier.
Early warning signs:
- Migration project focused on "lift and shift" rather than simplification
- No custom code usage analysis during transition
- Developers saying "we'll clean it up later" (spoiler: they won't)
2. The business still doesn’t trust standard
Many users push back on SAP standard processes because they believe they do not meet their requirements. Maybe it’s because the last “standard” they used was ECC-era. Maybe they’ve spent 15 years getting what they want via tweaks and workarounds.
What we see in practice: A logistics company implemented standard S/4 warehouse management, but users kept requesting custom reports because they “didn’t trust” the standard analytics. Result: 40+ custom dashboards recreating standard functionality.
Early warning signs:
- Business users immediately asking for "familiar" customizations
- No standard process training during S/4 rollout
- IT accepting "that's how we've always done it" as requirements
3. Your integration architecture is held together with duct tape
Clean core means more external services, more APIs, more moving parts. But if your integration architecture isn’t rock solid, or worse, if every team builds point-to-point connections , things break quietly.
What we see in practice: A financial services client built 12 different BTP apps, each with its own S/4 connection logic. When they needed to change authentication, they had to update 12 different systems. When one app failed, it took down three others.
Early warning signs:
- Teams building custom integration connectors for each project
- No enterprise integration strategy for BTP applications
- Data synchronization issues between core and extensions
4. Nobody actually enforces the rules
Even with clear clean core principles, what happens when someone breaks them? In many organizations: nothing.
What we see in practice: Architecture teams say no to in-core development, but project teams get it approved anyway. A retail client had “zero tolerance” for core modifications, but their vendor quietly delivered a custom pricing app that modified standard tables. No one noticed until an upgrade failed.
Early warning signs:
- Exceptions being approved without documentation
- No code review process for S/4 modifications
- Project timelines driving architectural decisions
5. You’re treating Clean Core like a technical problem
This is the biggest one. Clean core isn’t about code, it’s about how your entire organization makes decisions.
What we see in practice: A pharmaceutical company had perfect technical clean core guidelines, but their business prioritized “time to market” above everything else. When regulatory deadlines approached, clean core was the first thing sacrificed. After 18 months, they had 200+ undocumented core modifications.
Early warning signs:
- Clean core only discussed in IT meetings
- Business cases always emphasizing speed over sustainability
- No executive sponsorship for architectural decisions
What failure actually costs you
When clean core fails, the consequences compound:
Technical debt spiral: Your upgrade windows shrink from quarterly to annual. Change requests take months instead of weeks. Your system becomes fragile and unpredictable.
Team burnout: Developers spend 60% of their time on maintenance instead of innovation. Your best people start looking elsewhere.
Business credibility collapse: Once the business sees SAP as slow and inflexible again, they start looking for ways around it. Shadow IT flourishes. And you’re back where you started.
Real costs: One client calculated that clean core violations cost them €2.3M annually in additional maintenance, delayed upgrades, and extended project timelines.
The good news: you can turn this around
If you recognize your organization in these patterns, you’re not doomed to repeat the mistakes of the past. The companies that successfully implement clean core share common approaches, but it requires more than technical fixes.
It requires organizational change. Clear ownership. New skills. Different governance. And most importantly: a systematic approach that addresses the root causes, not just the symptoms.
The organizations that crack this code don’t just follow technical guidelines , they fundamentally change how they work. They make different decisions under pressure. They invest in capabilities, not just quick fixes.
Where do you stand?
Before you can fix clean core, you need to understand where you really are. Not where you think you are, or where your project reports say you are , but where you actually are.
That means honest assessment. Map your architecture, your custom landscape, your risk areas. Then frame the conversation inside your organization around what matters: business agility, system reliability, and long-term competitiveness.
The question is: are you ready to do the work?
In our next article, we’ll dive deep into the proven strategies that actually work: concrete governance models, skill-building strategies, and implementation roadmaps that separate the success stories from the cautionary tales.
Want to avoid the pitfalls most clean core initiatives face? Let’s talk about how to make yours a success.
