Summary
Last week, my research report on the Total Cost of Ownership (TCO) of used industrial machinery revealed that the initial purchase price is often just a small part of the overall financial burden. I demonstrated that significant costs are hidden in unplanned downtime, expensive repairs, and reduced efficiency.
This week, I want to take a deeper dive into the primary source of these problems: the control system. My analysis will show that when a machine’s control system becomes obsolete, it effectively “speaks a dead language,” cutting off access to manufacturer support and limiting its ability to integrate with modern operations.
1. What Is a Control System?
To the untrained eye, an industrial machine appears to be a complex assembly of motors, gears, and pipes. However, the heart of its operation is an electronic nervous system known as the control system.
Simply put, a control system is the brain of your machine. It’s the combination of hardware and software that governs how the machine operates, typically housed in a control panel.
Think of it as the coach of a soccer team, ensuring that every component—from motors to sensors—works in harmony to complete a task. It processes data from sensors (e.g., temperature, pressure, position) and sends commands to actuators (e.g., motors, valves, relays) to execute a specific task or sequence. This brain can range from simple relays and switches to modern Programmable Logic Controllers (PLCs) and Human-Machine Interfaces (HMIs).
Without a functioning control system, a machine is little more than a pile of metal components. It determines a machine’s speed, precision, safety, and overall reliability. Its condition is a key indicator of long-term performance. My research focuses on digital control systems, as these are used in almost all modern industrial equipment.
Unfortunately, the control systems found in used machinery are often a generation or two behind—and that’s where the trouble begins.
2. The Two Eras of Industrial Controls
Control systems evolve rapidly with technological advancements. For the purpose of this analysis, I categorize them into two broad eras:
The Modern Era
These are systems developed within the last 15–20 years. They are defined by modularity, digital networking, and strong manufacturer support. Typically based on PLCs and HMIs, these systems are still actively supported, with spare parts readily available. Importantly, today’s engineers are trained to work with them.
The Obsolete Era
These systems are no longer manufactured, sold, or supported. Once a control system is deemed “obsolete,” its original manufacturer ceases all support, including technical assistance, software updates, and parts availability. These systems often use proprietary programming languages, obscure hardware, and outdated communication protocols.
While some of these systems still function, they exist on borrowed time. Each failure introduces a high risk of permanent shutdown.
The transition between these eras has created a significant technological gap, which many used machines fall into.
3. The Hidden Risks of Running an Obsolete Control System
Operating a machine with an obsolete control system introduces several critical risks that directly inflate its Total Cost of Ownership (TCO). For buyers and operators, these risks translate into hidden and often escalating costs:
The Disappearance of Manufacturer Support.
When a manufacturer declares a product “obsolete,” it means they have ceased production and will no longer provide technical support, software updates, or new spare parts.
This leaves the end-user in a risky position. If a circuit board or a processor fails, you cannot simply order a new one from the factory.
The only options are to search for rare new-old stock, find a refurbished part, or have the component repaired by a specialist—all of which are costly and time-consuming processes.
Sourcing becomes a game of chance, relying on a small, expensive secondary market. The lack of support is a primary driver of the extended downtime and inflated costs I highlighted in my previous report.
The Knowledge Gap.
As technology advances, so too does the expertise of the engineering workforce. The manufacturer’s technical support lines no longer have experts who can troubleshoot problems with these old systems.
Engineers and technicians trained today are highly proficient in modern systems but often lack the skills and experience to work with control systems from decades past.
This creates a “knowledge gap”. The manuals and technical documentation may be out of print, making it difficult for even a skilled technician to diagnose an issue.
Finding a specialist who can diagnose and repair an obsolete system is a challenge, and their services command a premium, adding to maintenance costs.
You are left to your own devices or forced to find a niche expert, which is not always easy or affordable.
The Communication Barrier.
In the modern manufacturing environment, data is king. Businesses rely on information from the factory floor to track production, manage inventory, and make strategic decisions.
Modern industrial systems are designed to communicate with each other, sharing data on production metrics, energy usage, and more. However, obsolete control systems were designed in an era before the concept of interconnected factories.
They were built in an era before this kind of connectivity was common. They are unable to “speak” to modern manufacturing software or communicate with other machines on the production line, isolating the machine and hindering data-driven management.
That is hinder you from getting a full picture of your operations. This is a significant factor in reduced operational efficiency.
4. Conclusion:
The condition of a machine’s control system is a fundamental indicator of its long-term viability, far more so than its mechanical condition. A mechanically sound machine can be rendered useless by a single failed, irreplaceable component in its control system.
The obsolescence of a control system creates a domino effect. A small, seemingly insignificant hardware failure can halt an entire production line because a replacement part cannot be sourced quickly.
The lack of manufacturer support means that finding a solution takes much longer, increasing both repair costs and downtime. This domino effect is what turns a machine that seemed like a bargain into a long-term financial drain, eroding all the initial cost savings.
I urge all decision-makers to evaluate the control system of a used machine with the same scrutiny they apply to its mechanical components.
Ignoring this critical element is an invitation for operational bottlenecks and unexpected financial burdens.
An attractive price on a machine with an obsolete control system is often a deceptive bargain. A machine that cannot be easily repaired, supported, or integrated with your modern operations will inevitably cost you more in the long run.
In my next research report, I will continue this investigation by showing you how an obsolete control system can act as a bottleneck, preventing even the most skilled operator from maximizing the machine’s true potential.