Legacy system failures in critical infrastructure aren’t an abstract risk. They are a real threat that generates huge costs and paralyzes operations. Ignoring modernization leads to catastrophic financial and operational consequences. I’ll show you with a concrete example.
My years of experience confirm this: we’re not talking about general warnings. We’re dealing with measurable losses that hit budgets and reputations. Let’s act before it’s too late.
The price of stagnation in critical infrastructure
Critical infrastructure – transport, energy, healthcare – often relies on systems that are decades old. These solutions, once reliable, are now ticking time bombs. Their failures generate costs that far exceed the initial losses, leading to operational paralysis and safety hazards.
In 2023, the average cost of a data breach in the critical infrastructure sector reached $5.04 million. This clearly shows the scale of the problem.
€5 million: a concrete lesson from the past
Imagine this scenario: In the European transport sector, a key railway hub experiences severe disruptions. Italian authorities investigate these incidents as potential sabotage, linked to damaged and burned traffic control cables. This incident is a symbol of a wider problem.
Ignoring the modernization of legacy systems leads to catastrophic financial and operational consequences. This isn’t speculation, but real losses that also affect thousands of interrupted interactions.
My position is clear: a proactive approach to modernization is the only strategy. It minimizes the risk of failure in critical infrastructure. Waiting for the next “glitch” is asking for a disaster.
The mechanics of a €5 million disaster
Let’s look at how such a failure can escalate into a full-blown catastrophe.
Anatomy of a failure: how one bug triggered a cascade
In our example, a seemingly minor fault in an outdated system module triggered a domino effect. For instance, a date-handling bug that didn’t account for the next leap year. This module, responsible for train scheduling, started generating incorrect data.
The complexity and hidden dependencies in the legacy architecture made it impossible to quickly identify and isolate the problem. Operational Technology (OT) systems in critical infrastructure were often designed with availability as the priority, not logging or alerting mechanisms. This makes them particularly vulnerable not only to attacks but also to internal failures.
What were the direct operational consequences? Paralysis of part of the railway network, hundreds of delays, errors in ticket billing, and loss of data on the current status of trains. Organizations need an average of about seven months to fully restore operations after a cyberattack or a major failure.
The invisible costs: losses beyond the repair bill
That €5 million is just the tip of the iceberg. The real costs include lost revenue from the inability to provide services – canceled connections, ticket refunds, and the inability to transport goods. Large companies lose an average of $9,000 per minute of downtime.
Then there are regulatory fines and compensation for customers, which often exceed the direct repair costs. For example, the 2024 attack on Synnovis caused delays in over 1,100 cancer treatments and about 2,000 canceled outpatient appointments, significantly impacting patients.
Breaches resolved in less than 200 days generate 23% lower costs. And let’s not forget the tarnished reputation, loss of partner trust, and difficulties in securing new contracts. These have long-term financial consequences that are hard to estimate but very real.
| Cost Aspect | Cost of Legacy System Failure | Cost of Proactive Modernization |
|---|---|---|
| Direct repairs/implementation | 2.5 mln EUR | 1.5 mln EUR |
| Lost revenue/production | 1.5 mln EUR | 200 tys. EUR |
| Penalties and compensation | 1 mln EUR | 0 EUR |
| Crisis management costs | 500 tys. EUR | 50 tys. EUR |
| Staff training and adaptation | 200 tys. EUR | 300 tys. EUR |
| Loss of trust/reputation | Immeasurable, high | Low, increased trust |
Lessons from the fire: how to avoid your own multi-million disaster
What can we do to avoid repeating such mistakes?
The visibility problem: mapping dependencies and risks
My experience shows that the key is to understand the hidden dependencies in old systems. A lack of documentation and the departure of key engineers create “black boxes.” They make it impossible to predict the consequences of any change.
I stress the need for inventory and architecture mapping, even if it requires reverse engineering. This is the first step to controlling risk. You can’t protect what you don’t know. Without a full picture of dependencies, every change in a legacy system is a game of Russian roulette.
Proactive strategy: from quick fixes to transformation
Patching and ad-hoc “band-aid solutions” are a road to nowhere. They only postpone the inevitable and increase costs in the long run. Some managers might ignore the root causes of downtime to limit current expenses, which can be seen as a short-sighted strategy.
There are proven modernization strategies, such as the Strangler Fig Pattern or gradual refactoring. They allow for a controlled migration of functionality without interrupting the system’s operation. Proactive modernization requires strategic prioritization based on system criticality. It also demands intensive investment in developing cybersecurity competencies, especially in Operational Technology (OT).
A strategic modernization plan, not just reacting to crises, is the only path to security and efficiency in critical infrastructure. Upcoming regulations, like the EU Cybersecurity Act, may in the future require boards to conduct periodic briefings and simulation exercises, but specific deadlines are still uncertain. They are also expected to promote the use of APIs to isolate legacy systems.
Counterarguments: is modernization always a risk?
I often hear that modernization is too risky or too expensive. Let’s take a closer look.
The ‘too expensive to change’ myth
Modernization requires investment, that’s a fact. But it’s an investment that prevents much larger, uncontrolled costs of failure. It’s like disaster insurance.
Is maintaining an old, unreliable car cheaper than buying a new, safe, and efficient one? Short-term savings often lead to long-term losses. The costs of maintaining outdated systems (licenses, specialized staff, security risks) often exceed the costs of modernization over a few years.
In 2023, the US government allocated $80 billion – 80% of its IT and cybersecurity budget – to maintaining legacy systems. These are astronomical sums that could have gone toward development.
The risk of change or the certainty of failure?
Concerns about the risk of introducing change are understandable. My position, however, is clear: not changing is a guarantee of failure. It’s not a matter of “if,” but “when” and “on what scale.”
Outdated or unpatched IT systems, known as technical debt, are often the first vulnerability exploited by attackers to paralyze key operations. The controlled risk of a well-planned and managed modernization is much smaller than the uncontrolled risk of a catastrophe that could strike at any moment.
As many as 60% of security breaches in the European Union result from known, unpatched vulnerabilities. In today’s world, technology evolves so quickly that stagnation means regression. It also increases exposure to threats, especially in the context of cybersecurity. The “if it ain’t broke, don’t fix it” myth encourages maintaining systems like a 2005 SCADA running on an un-updated Windows XP, drastically increasing its vulnerability to attacks.
My diagnosis – time for radical decisions
After analyzing incidents like the €5 million one, there’s no room for half-measures.
A necessity, not an option: the future of critical infrastructure
Modernizing legacy systems in critical infrastructure is not an option, but an absolute necessity. My personal conviction, born from years of experience, is that decision-makers must treat modernization as a strategic priority, not just another line item in the IT budget.
Critical infrastructure operators must prepare for unannounced audits and costly system migration programs resulting from regulations like NIS2 and the EU Cybersecurity Act 2026. This will help them avoid fines that could reach hundreds of millions of euros. I’m calling for courage in decision-making because the consequences of inaction are too high – both financially and socially.
What will you do with your ‘ticking time bomb’?
Every organization with legacy systems has a “ticking time bomb” like this.
The future is now: act before it’s too late
I’ll ask you directly: are you waiting for your own multi-million-euro failure? Are you prepared to bear the costs of inaction, which go far beyond direct losses?
I encourage decision-makers to immediately start an audit of their legacy systems, identify risks, and create a strategic modernization plan. A fundamental step is to conduct a comprehensive asset inventory.
I invite you to discuss, share experiences, and find solutions together. The future of critical infrastructure depends on the decisions we make today.
Tomasz Michalik
