The Decoupling Strategy: Modernising Legacy Systems Without Production Downtime

Reliable legacy systems keep production running but often stifle the agility businesses need. Decoupling software from hardware resolves this contradiction. It enables plant modernisation during live operation—eliminating costly equipment replacement and preventing risky downtime.

 

They rarely announce themselves and almost always bring significant financial losses: breakdowns and failures in production facilities. In many cases, they can be avoided, particularly when they are caused by outdated systems. Yet many companies still shy away from modernising their plants and IT infrastructure, fearing that any change could jeopardise operations. It’s an understandable concern, but it comes at a price: across manufacturing, facilities are running equipment commissioned thirty or forty years ago. These machines work reliably and secure daily value creation. But this proven infrastructure reaches its limits when markets demand rapid adaptation. Supply chain bottlenecks, skilled labour shortages and pressure for greater efficiency all require flexible production.

 

International corporations and highly specialised small and medium-sized enterprises (SMEs) alike must modernise. Regardless of company size, executives and production managers face the same challenge: the market demands speed, whilst the physical factory cannot tolerate downtime.

 

The split between innovation pace and operational security

IT and OT pursue different goals. Whilst information technology (IT) demands rapid innovation, transparency and agility, operational technology (OT) centres on reliability. Production managers bear responsibility for uptime, product quality and workplace safety. Any change to a live system carries risk. On the shop floor, there’s often a palpable fatigue towards abstract IT debates. The fear of unplanned stoppages isn’t a convenient excuse—it’s operational reality.

 

True convergence doesn’t force OT to awkwardly “IT-ise” itself. Rather, it’s about learning from IT and integrating its agility in ways that always preserve safety and productivity. A complete replacement of functioning machinery (so-called “rip and replace”) is usually ruled out on economic and operational grounds. What’s needed are pathways that protect existing investments whilst unlocking new digital capabilities.

 

Specialist machinery manufacturer Bausch+Ströbel demonstrates how such legacy modernisation works in practice without production stoppages. Together with condition-monitoring specialist Brüel & Kjær Vibro and AVEVA, the company retrofitted pharmaceutical filling lines during live operation with wireless vibration sensors. These could be installed during regular maintenance without touching the machine controls and without costly requalification of the facility. Vibration, machine and process data now converge in the AVEVA PI System, delivering concrete recommendations directly to operators on the line. Unplanned shutdowns can be identified early and prevented before an entire batch is lost.

 

The difference between genuine value and the pilot trap

This project’s success is no accident—Bausch+Ströbel didn’t begin with an unfocused technology experiment, but with the solution to a concrete, business-critical problem. Herein lies the difference from many other digitalisation initiatives. Research paints a sobering picture: according to the Boston Consulting Group’s study “Flipping the Odds of Digital Transformation Success”, 70 per cent of all digital transformation projects fail to meet their targets for time, budget and scope. They result in a dead end and never progress beyond a pure proof of concept (PoC).

 

A key reason for this PoC trap is a classic misunderstanding at the interface: whilst IT often launches technology-driven pilots, OT needs practical solutions with a reliable scaling path from day one. Successful transformation only happens when both departments jointly define the concrete operational pain point before the first line of code is written. Transformation must never be a mere end in itself.

 

Software-defined automation (SDA): The bridge between legacy and modern IT

Decoupling software from hardware is the critical first step in modernisation. The principle is as simple as it is powerful: existing hardware continues running unchanged, whilst new functions, applications and use cases are flexibly introduced via a higher-level software layer. Instead of completely replacing a functioning control system, standardised interfaces establish a direct bridge between proven physical infrastructure and modern IT intelligence.

 

This approach resolves the classic departmental conflict in a pragmatic way: OT retains full control over the stability and safety of physical plants, whilst IT gains the flexibility needed to implement new data-driven applications agilely on the software layer. It protects investments already made and brings the dynamism of the software world directly to the factory floor.

 

From cost centre to ROI: steering transformation economically

For decision-makers, this software-defined automation is no mere technical detail. Instead, the technology serves as a business instrument for long-term resilience. The decoupling strategy directly addresses two central challenges:

 

1. Capital investment protection (CAPEX): Instead of prematurely scrapping expensive machinery, the software layer extends its service life. This conserves the capital budget and protects investments already made.

 

2. Operating costs (OPEX): Improved data transparency reduces unplanned downtime and proactively optimises maintenance intervals.

 

At the same time, this approach relieves skilled personnel. Instead of spending valuable working time manually consolidating data in complex spreadsheets, teams have visual, intuitive dashboards at their disposal. This accelerates well-founded decisions directly on the production line.

 

That this concept also works at scale with highly complex infrastructure is proven by European energy supplier Vattenfall. As Europe’s third-largest hydropower provider, the Swedish company faced the challenge that existing legacy facilities delivered no real-time insights. By deploying the AVEVA PI System, Vattenfall switched to predictive, condition-based maintenance. Without compromising day-to-day operations, the company was able to reduce its maintenance costs by 1.5 per cent in the first year alone.

 

Sharing insights, not exposing data

Particularly in the DACH region, data protection concerns and fear of loss of control in the cloud often slow progress. Yet genuine digitalisation doesn’t require the uncontrolled disclosure of internal operational know-how. It’s not about data sharing (sharing raw data), but about insight sharing (sharing derived knowledge). Platforms such as AVEVA CONNECT provide vendor-neutral structures where companies themselves determine which data they share and which they don’t. They retain full control over their physical systems, whilst simultaneously creating the transparency needed in a digital ecosystem to make informed decisions.

 

Industrial companies can no longer afford to postpone transformation indefinitely. Nobody needs to replace functioning facilities overnight. A well-considered modernisation strategy protects existing investments, makes data usable and implements changes incrementally. From the outset, modernisation must not remain a pure IT project: it must be strategically anchored at leadership level.

 

Want to dive deeper into the topic and hear compelling perspectives from both IT and OT? Find the first episode here.