As organisations deploy new digital capabilities and platforms, they consistently hit the same wall: the old systems and long-standing vendor contracts that keep daily operations running. These legacy systems, built for a different era, can make it harder to capitalise on new opportunities.
Unlike new initiatives, which are designed with cloud, APIs, and modularity in mind, much inherited infrastructure was built in an earlier era when processes were certain, and stability was essential. That legacy brings unforeseen inefficiencies. Maintaining it can consume resources and highlight areas for improvement, and modernisation decisions often require thoughtful trade-offs.
We explore what those challenges mean in practice and how businesses can navigate the complex path between maintenance and long-term resilience.
Growing Burden of Ageing Infrastructure
Many business-critical systems in large organisations have legacy systems that only a few specialists still understand long after their initial implementation.
These systems are not broken. In fact, their long lifespans are a testament to their robustness. But extending their lifespans requires increasingly specialised support and careful management. Some of the challenges that emerge over time include:
- Rising maintenance costs: As vendors phase out support, organisations must pay a premium for expertise or run the risk of outages.
- Security vulnerabilities: Older software can become harder to secure as patch cycles slow, with patches becoming rarer over time.
- Integration challenges: Older systems resist connection to modern tools, creating bottlenecks when data must flow across departments.
Vendor Lock-In: From Tailored Fit to Strategic Constraint
Many of these legacy systems were not generic; they were custom-built to fit the exact needs of a business unit. At the time, this made sense.
Vendor lock-in occurs when a company cannot easily switch providers or adopt new tools without incurring new costs or disruption. For example:
- A chemical company may rely on a proprietary supply chain platform that cannot integrate seamlessly with newer sustainability reporting systems.
- A finance system may require the vendor’s permission for every major upgrade, slowing the adoption of new features.
- Data stored in closed formats may make it difficult to migrate
This can lead to disconnected processes. Businesses optimise locally with their vendors but lose the ability to coordinate globally. Especially for large-scale group companies which depend on synergy between divisions, this could create coordination challenges.
How to Understand Whether You Have Legacy Systems
Technical expertise is not needed to recognise legacy systems; the signs usually show up in day-to-day operations.
1. Heavy reliance on Excel
If teams regularly export data, build their own trackers, or complete key workflows in spreadsheets, it usually means the core system can’t meet the business’s needs. This Excel use case indicates that the core system may not fully support evolving workflows.
2. Slow or risky system updates
If updating a system feels disruptive, requires long vendor cycles, or people avoid making changes because “something might break,” the system may be signalling that an update is due.
3. Poor integration
When data must be moved manually between systems through CSV files, email attachments, or copy-paste, then it signals that the platform wasn’t designed for today’s connected workflows.
4. Dependence on a few experts or a single vendor
If only one person (or the vendor) has the knowledge on how a system works, it can create operational bottlenecks over time.
5. Normalised workarounds
When the main system can’t keep up with how the business operates, shadow processes such as multiple side tools, manual approval steps, or parallel spreadsheets emerge.
Modernisation Choices: Lift-and-Shift vs. Rebuild
Once an organisation accepts the need to modernise, it faces a fundamental choice: “Should we migrate existing systems as they are, or rebuild them entirely?”
Lift-and-Shift
This approach moves current systems to modern infrastructure (often cloud) with minimal change.
- Benefits: faster, cheaper in the short term, lower migration risk.
- Limits: may retain some of the previous design limitations.
Rebuild
This approach redesigns systems from the ground up to leverage modern capabilities.
- Benefits: enables automation, integration, scalability, and futureproofing.
- Limits: more expensive, longer timelines, requires more deliberate organisational alignment.
Hybrid
Most organisations end up with a hybrid approach. For example, in the energy sector, grid-monitoring tools might justify a full rebuild to allow predictive analytics and IoT integration. Meanwhile, HR systems may simply be lifted into the cloud to reduce costs without requiring reinvention.
The question is not “which is better?” but “which is right for this system?” A portfolio view of classifying systems by criticality, lifespan, and strategic value allows organisations to make deliberate, balanced choices.
Culture as an Underlying Factor
While much discussion focuses on technology, modernisation is ultimately about people. Teams accustomed to established tools may prefer predictable change.
These concerns deserve attention, but thoughtful planning allows progress without unnecessary disruption. The cost of delay is real and compounding.
Successful modernisation programs tend to disperse change management throughout the process rather than isolating it. Pilot projects prove value in small areas. Training ensures staff are equipped to adopt new systems. Leadership alignment keeps objectives clear and consistent.
In this way, confidence builds gradually as teams see value delivered in manageable steps, allowing progress to build incrementally and sustainably
The Strategic Value of Modernisation
Although legacy discussions often get reduced to comparing maintenance costs with the price of upgrades, the real value of modernisation goes far beyond budgets. Its impact comes from what it unlocks
- Faster decision-making: When systems share data seamlessly, leaders can act on real-time insights rather than reconciled reports.
- Resilience in disruption: Modern systems can adapt to supply shocks, regulatory changes, or market volatility more quickly.
- Future readiness: Cloud-native, modular architectures create a foundation for AI, automation, and cross-business innovation.
A chemicals business may need to comply with evolving EU disclosure requirements. A logistics business may need to reroute shipments in real time. An energy business may need to integrate renewable assets into legacy grids. Modern platforms make these capabilities far easier to deliver at speed and scale.
Conclusion
Every enterprise eventually faces a choice: continue maintaining the systems of the past or invest in the platforms of the future.
Long-standing infrastructure introduces considerations that go beyond financial cost: it slows adaptation, increases risk, and limits innovation. Vendor lock-in can further slow transformation by tying critical functions to proprietary systems that resist integration. And modernisation decisions such as whether to lift-and-shift or rebuild each demand careful judgment about cost, value, and future potential.
There is no one-size-fits-all answer. But what is clear is that modernisation must be treated as a strategic discipline, not a side project. It requires deliberate choices, a willingness to rethink some longstanding vendor relationships, and a recognition that digital uplift is not just about IT, but it is about resilience, competitiveness, and long-term growth.
The organisations that move decisively will not only reduce costs but will also position themselves to innovate continuously, integrate broadly, and respond flexibly in a world where change is constant. Those who move early are best positioned to unlock new opportunities that legacy systems can otherwise hold back.
Where to Start?
At SCSK {digital}, we support organisations at every stage of modernisation from assessing legacy constraints to designing target architectures, migrating workloads, and embedding scalable operating models. With experience across complex enterprise environments, we help businesses reduce transformation risk while accelerating the shift toward flexible, future-ready platforms.
Contact us for more information.
Author:
Simranjeet Riyat, AI Consultant
