Programmable Logic Controllers (PLCs) have been around for decades and have become a vital part of industrial applications. They are widely used to control and monitor complex machinery and processes across manufacturing, logistics, energy, and other industries.
PLCs are designed to withstand harsh industrial environments and operate for long periods without interruption. However, even the most reliable PLCs become outdated over time, requiring upgrades to ensure efficiency, security, and integration with modern technology.
According to Advisory Group many industrial facilities still rely on aging PLC systems, with over 50% of them operating controllers that are more than a decade old. While these systems were once cutting-edge, the risks of running outdated automation technology are growing. Unplanned downtime alone costs industrial manufacturers a staggering $50 billion each year based on Deloitte, often stemming from failing components, obsolete software, and a lack of modern predictive maintenance strategies. Moreover, for manufacturers, the impact of downtime is relentless—on average, equipment failures result in 800 hours of lost productivity annually, or more than 15 hours every single week.
Beyond financial losses, outdated PLCs pose a serious security threat. Cyber-attacks on industrial organizations remained prime targets, with 70% of ransomware attacks affecting manufacturing entities across 33 unique manufacturing subsectors, leaving vulnerable systems exposed to operational disruptions, data breaches, and costly shutdowns (Source: Dragos Security Report). “Industrial and critical infrastructure has been moving away from highly customized facilities to ones that—for good economic and productivity reasons—share the same industrial devices, technologies, and facility designs across sites and sectors.” – said Robert M. Lee, Co-founder and CEO of Dragos.
These numbers highlight a growing reality: upgrading to modern PLC systems isn’t just about improving efficiency—it’s about safeguarding operations. If your PLC system in the industrial automation industry has been in place for years without a significant upgrade, it may be limiting your operational potential. Below, we explore the top five signs that indicate your PLC system needs modernization and how upgrading can enhance performance, reduce downtime, and ensure future scalability.
1. Obsolete Hardware or Software
One of the biggest warning signs that your PLC system needs an upgrade is hardware and software obsolescence. As technology advances, older PLC models lose manufacturer support, making maintenance, troubleshooting, and integration increasingly difficult.
Many businesses face the frustration of limited spare parts availability, where sourcing replacement components becomes both time-consuming and costly. Compatibility issues further complicate operations, as newer industrial devices and software struggle to integrate with outdated PLCs. Without firmware updates, security patches, or technical support, manufacturers are left with systems that lack reliability and resilience.
As Industry 4.0 continues to evolve, a significant portion of industrial automation systems will require upgrades to remain compatible with modern technologies. Companies that fail to modernize risk falling behind digital transformation (Source: McKinsey & Company).
Yet, many facilities still run on legacy S7-400 and S7-300 PLC’s systems, long discontinued by Siemens. Holding onto outdated technology may seem like a cost-saving measure, but in reality, it increases long-term risks and inefficiencies. Migrating to a modern PLC platform is no longer just an option—it’s a necessity for ensuring long-term support, seamless integration, and future-proof automation.
2. Frequent System Failures and Downtime
As PLC systems age, they become increasingly vulnerable to unplanned breakdowns, causing disruptions in production, costly downtime, and operational inefficiencies. An outdated PLC often exhibits warning signs—unexpected shutdowns halt operations, error messages become more frequent, and maintenance costs steadily rise due to failing components and limited spare parts availability.
These challenges are not just operational headaches—they are a clear sign that your PLC system needs an upgrade. According to Forbes, the financial impact of downtime is staggering. Industrial downtime costs industrial manufacturers up to $50 billion annually, leading to significant productivity losses, operational inefficiencies, and increased maintenance expenses with aging PLC systems being a major culprit.
In industries like automotive manufacturing, every minute of halted production can lead to losses of up to $22,000, claimed Deloitte. Even planned shutdowns come at a price, consuming 1%–10% of total available production time, time that cannot be recovered.
3. Inability to Integrate New Technology
As industrial automation evolves, technologies like IoT, AI, and cloud computing are reshaping the market. However, legacy PLC systems struggle to keep up, often lacking the necessary compatibility to integrate with modern industrial ecosystems. Without support for modern communication protocols such as Ethernet/IP, MQTT, or OPC UA, older PLCs become isolated, unable to connect with IoT sensors, analytics platforms, or cloud-based control systems.
This limitation extends beyond simple connectivity—remote monitoring and advanced diagnostics become increasingly difficult, forcing manufacturers to rely on manual interventions and outdated maintenance strategies. As industries push toward smart manufacturing and predictive maintenance, real-time data analysis is essential—yet many legacy PLCs simply weren’t designed to handle this level of integration.
The integration of PLCs with IoT is no longer a futuristic concept—it’s a critical step for manufacturers striving to remain competitive. Industrial automation investment is increasing, with 92% of businesses planning to maintain or increase their spending on automation in the next year, according to a survey by SMA Technologies. However, a significant portion of these organizations may still be relying on outdated PLCs, which could lack the necessary capabilities to fully support modern IoT-driven advancements. Without upgrades, these legacy systems create bottlenecks, limiting scalability, flexibility, and overall operational efficiency.
Failing to modernize PLC infrastructure means missing out on predictive analytics, real-time monitoring, and cloud-based automation, which are crucial for minimizing downtime, optimizing production, and driving profitability. The shift to smart manufacturing requires connected, data-driven automation, making IoT-integrated PLCs the foundation of next-generation industrial operations.
4. Decreased Performance and Efficiency
One of the clearest signs that your PLC needs an upgrade is sluggish processing times, which can lead to inefficiencies across your operations. When a PLC struggles to process commands quickly, it delays critical actions, causing bottlenecks in production and reducing overall system performance.
Imagine a high-speed packaging line where thousands of products move along the conveyor every hour, each relying on real-time sensor data to be sorted and labeled with precision. Everything runs smoothly—until an aging PLC begins to lag. Suddenly, labels are misapplied, barcodes don’t scan correctly, and sorting errors pile up. Workers scramble to fix mistakes, but the delays ripple through the entire operation. The once-efficient line slows to a crawl, waste bins fill with discarded packages, and production targets slip further out of reach. What was once a seamless process has now become a costly bottleneck—all because of an outdated PLC struggling to keep up with modern demands.
Modern automation upgrades have consistently demonstrated significant benefits. For example, Pfizer’s new high-containment manufacturing facility in Freiburg, Germany, implemented Siemens technology and services, resulting in a 40% reduction in energy use in its environmental control system compared to traditional facilities. This demonstrates how upgrading to more advanced systems can significantly improve efficiency, reduce operational waste, and lower energy consumption.
5. Limited Data Processing and Storage Capabilities
Real-time data collection, analytics, and predictive maintenance have become essential for optimizing efficiency. However, many older PLCs struggle to keep up with these demands due to their limited processing power, memory capacity, and storage capabilities. As industrial operations generate vast amounts of data, legacy PLCs often run out of memory, causing slowdowns, system crashes, and incomplete data logs. This makes troubleshooting difficult and prevents manufacturers from leveraging valuable insights to improve efficiency.
Beyond performance issues, outdated PLCs also limit automation scalability, as they lack the ability to handle large-scale sensor inputs or integrate with AI-driven automation. Without edge computing and cloud integration, industrial systems relying on legacy PLCs remain disconnected from advanced data analytics and real-time monitoring, significantly impacting productivity. According to the Manufacturing Institute, real-time data access can boost production efficiency by up to 20%, yet many struggle to achieve these results due to outdated automation infrastructure.
To stay competitive, businesses must upgrade to modern PLCs equipped with enhanced data processing, cloud connectivity, and AI-driven automation capabilities. These upgrades eliminate bottlenecks, improve system reliability, and unlock the full potential of data-driven industrial operations. Holding onto legacy systems may seem cost-effective in the short term, but in reality, it leads to missed opportunities, operational inefficiencies, and reduced competitiveness in an increasingly digital industrial world.
Is It Time to Upgrade?
If your PLC system shows any of these warning signs, delaying an upgrade could cost you more in downtime, maintenance, and lost efficiency. Investing in modernization ensures your industrial processes remain efficient, secure, and competitive in the digital era.
Need Expert Assistance?
Not sure if your system needs an upgrade? Our PLC specialists can conduct a comprehensive assessment of your current setup, identifying weak points, inefficiencies, and security vulnerabilities. We’ll provide a detailed upgrade strategy tailored to your industry, ensuring seamless integration with modern automation technologies. Schedule your Industrial PLC Assessment today.