Originally published on Control Engineering Europe
While enterprise IT refresh cycles are typically five years or less, it’s a different story in the world of Operational Technology (OT). Many DCSs are still automating industrial operations twenty years or more after commissioning.
DCS failure rates rise steadily after decades in active service. While systems may still be functional, their behaviour becomes more unreliable and harder to maintain. Components in analogue I/O modules inevitably degrade over time, leading to growing measurement inaccuracies. Similarly, the reliability of servers and operating systems becomes progressively compromised as vendor support dwindles and updates cease, after becoming obsolete or unsupported.
Suboptimal performance is compounded by a corresponding weakening in system resilience and recovery. If hardware failure occurs spare parts may no longer be readily available. What may have been a short interruption can quickly escalate to days or weeks of lost production.
Cybersecurity meanwhile becomes a critical concern for DCS architectures designed in a less hostile pre-IoT world. Unsupported operating systems, applications and services present an expanding digital attack surface. Outdated or end-of-life firmware is frequently unpatchable. And even when OT is air-gapped from enterprise IT networks, it is still vulnerable to compromise via portable media or temporary connections.
Of equal concern is a knowledge loss as thousands of engineers retire from the industry, taking decades of hard-won skills and insight with them. Abnormal plant conditions typically require expert manual intervention to recognise and mitigate process deviations or equipment failures. Veteran engineers use their expertise to identify unusual behaviours. With their departure, fault-finding times and operational risk increase during anomalous episodes.
Collectively, these DCS legacy challenges threaten production continuity and profitability. But what steps can engineering staff take to manage these concerns and extend the value of their automation assets?
Control system obsolescence can be addressed in two ways – either via full replacement or stepwise modernisation. While the one-off cost and risk of a brand-new DCS tempers enthusiasm for ‘rip and replace’ upgrades, incremental upgrades to controllers, I/O, operator workstations and servers can restore performance and resilience. ABB’s Automation Extended program, for example, allows existing ABB DCS users to future-proof their investments while adding new digital capabilities such as AI-driven analytics, condition-based monitoring and asset optimisation.
Cyber threats can be addressed in today’s control platforms. Secure by design, they offer protection against external attack via a range of measures including firewalls, intelligent intrusion detection and zero-trust authentication frameworks.
Modernising outdated automation platforms also provides an opportunity to safeguard engineering intellectual capital that’s threatened by changing workforce demographics. AI and machine learning can capture expert knowledge, helping guide systems to detect and react intelligently to anomalous situations. These insights can be translated into standardised, intuitive graphical environments that are readily accessible to the next wave of digital-native engineering talent.
Planned evolution is always preferable to forced replacement. Running automation systems to the point of inevitable failure robs organisations of control, pressuring plant owners to make costly short-term decisions that can jeopardize production continuity and staff safety.
Enhancing plant efficiency, sustainability and security, strategic modernization also reinforces the value of human workers. It frees process control engineers from error prone manual tasks, allowing them to focus their skills and energy on achieving higher business goals.
Volker Jung is Global Head of Modernization at ABB Energy Industries Service.
