How to Evaluate and Secure an Industrial Control System

Industrial control systems (ICS) are the backbone of large-scale production, distribution, and critical infrastructure operations. But today’s systems are no longer just about automation — they are strategic enablers of uptime, data-driven optimization, and cybersecurity resilience.

As industries face increasing pressure to boost throughput, comply with evolving standards, and reduce the risk of unplanned downtime, ICS upgrades have become a high-impact investment. 

For many ICS operators, operational technology (OT) secure remote access software is the most efficient and secure method for connecting to ICS environments when located off-site. This software secures business-critical operations and helps operators manage access to connected machinery or equipment.

This article helps you align your control architecture with long-term operational goals, whether you’re modernizing a legacy plant or deploying ICS across distributed assets.

Types of ICS and when to use them

Several types of ICS can monitor, control, and automate the industrial processes that many industries need. Distributed control systems and supervisory control and data acquisition systems are the most commonly used types.

Distributed control systems (DCS)

For centralized production systems, DCSs are the best option. They transmit a setpoint to the main controller, which then directs every connected valve to operate in a way that maintains this setpoint.

Data from a DCS can be stored for later reference or used to connect various local controllers centrally. This means businesses can quickly review production and operational data and make updates where necessary. Having multiple devices connected via a DCS also reduces the impact on the whole system should a single device or automation fail.

DCS is typically used in industries like manufacturing, water treatment, and chemical plants, where all production takes place in a single location.

Supervisory control and data acquisition (SCADA)

A SCADA system does not provide controllers with total control in the same way a DCS does; rather, it plays more of a supervisory role. Different components are connected within the SCADA and then distributed across various locations or plants.

Unlike a DCS, SCADA systems are ideal for managing operations across several locations from one centralized hub. Data is acquired and transmitted remotely, making it easier for workers to gather information and perform tasks without traveling to each plant location. This is why they’re typically used in field-based industries, such as oil (pipeline management) and energy (electrical transmission and distribution).

Key components of an ICS and how they interact

Within the ICS are various components that are required to connect the system and ensure that all elements are working correctly. Without these, the ICS cannot detect data or control operations from a remote system.

Human-machine interference (HMI)

The HMI is an essential part of the ICS, providing a graphical user interface (GUI) for a human operator to interact with the controller hardware. Status information can be displayed here, along with historical data gathered by the ICS. From the HMI, the controller can also configure setpoints and adjust any automation within the system.

Intelligent electronic devices (IED)

The IED is a smart device built into the ICS that acquires data and processes communication between connected devices. Using IEDs means that no matter what type of ICS is being used, locally controlled devices can be set to run automatically and controlled remotely.

Programmable logic controllers (PLC)

PLC hardware controls the overall system in DCS and SCADA systems, with local management possible through sensors and actuators. In smaller ICSs, PLCs are the primary components that configure automation and controls within the system.

Remote terminal units (RTU)

An RTU is a microprocessor that sends and receives information from the master terminal, typically in a SCADA system. The commands received by this processor control field devices while ensuring all necessary data is passed back to the central system for analysis and storage.

How to choose the right industrial control system for your industry

Selecting an industrial control system (ICS) is more than a technical decision. The system you choose will directly affect uptime, regulatory compliance, and how well your teams can scale or respond to failure.

While DCS and SCADA are the most commonly used ICS types, the right choice depends on your facility type, operational footprint, and long-term goals.

Start by mapping your operational scope

Understanding where and how your operations run helps determine whether a distributed or supervisory system makes sense.

• Single-site, continuous operations: A distributed control system (DCS) works best for centralized environments where timing and feedback are critical. This includes facilities like food processing plants, pharmaceutical lines, and chemical manufacturing sites.
• Remote or multi-site operations: If your assets are spread across a wide region, a SCADA system is more appropriate. SCADA allows teams to monitor and control distributed infrastructure from a central hub, without having to physically access each site.

Consider your environmental and connectivity constraints

The physical environment often dictates the kind of hardware and communications your ICS needs to support.

• Use PLCs when equipment is on-site and must respond to inputs in milliseconds, such as in car assembly lines or bottling plants.
• Use RTUs in outdoor or remote environments where power supply may be limited and data needs to be relayed over wireless or satellite networks.

Assess integration needs and legacy system compatibility

Most facilities already have some form of automation in place. The right ICS should be able to integrate with those systems rather than require a complete rip-and-replace.

Look for platforms that:

• Use open communication protocols like Modbus, OPC UA, or IEC 61850
• Provide built-in support for cloud integration or external analytics platforms
• Offer APIs or connectors for ERP, MES, and compliance reporting tools

Review your security and compliance requirements

Industrial environments are a high-value target for cybercriminals. A secure ICS should support more than just password protection.

• Check for built-in role-based access control (RBAC) and detailed audit logging
• Ensure the platform can integrate with your organization’s existing SIEM or identity provider
• Review whether the vendor complies with standards like NIST, NERC CIP, or IEC 62443

If your business is in a regulated space such as pharmaceuticals, oil and gas, or power generation, an ICS with built-in support for compliance reporting will reduce audit complexity later.

Implementing ICS: Key considerations for IT and OT teams

Deploying an industrial control system (ICS) involves far more than plugging in devices or configuring automation scripts. It requires coordination between IT and operational technology (OT) teams, careful planning around system architecture, and long-term strategies for both cybersecurity and system performance.

Here's an outline of the most critical steps for teams preparing to roll out or upgrade ICS infrastructure.

Align IT and OT goals early in the planning process

One of the biggest barriers to ICS success is misalignment between departments. OT teams prioritize uptime, machine availability, and deterministic response. IT teams focus on security, scalability, and data integration. Without early collaboration, these priorities can conflict.

Recommendation: Involve both IT and OT stakeholders from day one. Develop a shared project charter that includes:

• Clear roles for network security, device management, and change control
• Agreements on system uptime targets, patching schedules, and access control
• Definitions for what success looks like after rollout (e.g., improved OEE, faster MTTR)

Build an architecture plan that accounts for existing infrastructure

Most facilities already have partial automation or legacy ICS components in place. Replacing everything at once is not realistic for most budgets or production schedules.

Implementation best practices:

• Perform a detailed asset inventory to identify equipment that can be reused, virtualized, or phased out
• Create a segmented network design that separates critical ICS functions from enterprise IT systems
• Choose hardware that supports both new and legacy communication protocols to reduce transition friction

Don’t overlook operational training and lifecycle support

Even the most sophisticated ICS deployment can underperform if staff don’t understand how to use it — or worse, make costly errors.

• Schedule hands-on training before and after go-live
• Document SOPs for fault isolation, device replacement, and HMI updates
• Establish support contracts with vendors or integrators for long-term updates and patch management

A recurring maintenance and update plan should be part of the implementation scope, not an afterthought.

Securing your ICS: Threat landscape and mitigation strategies

Industrial control systems were once isolated and air-gapped. Today, increased connectivity, remote access, and integration with enterprise IT have made them prime targets for cyberattacks. A compromised ICS can halt production, damage physical assets, or even create life-threatening conditions in critical infrastructure.

Protecting ICS environments is no longer optional for decision-makers; it’s a foundational requirement. This section outlines the most relevant threats and the security practices that operations and security teams must adopt to mitigate them.

Key threats facing ICS environments

• Phishing and credential misuse: Many ICS breaches start with compromised user accounts, often due to phishing or poor password hygiene.
• Ransomware targeting OT: Malware like Ekans and Snake are designed to disable industrial systems and encrypt controller access.
  
• Legacy vulnerabilities: Outdated firmware and hardware often lack modern protections and are rarely patched.
• Unsecured remote access: Vendor portals and VPNs, if not segmented, can become backdoors into control networks.

Core strategies to reduce ICS risk

• Segment control networks: Separate ICS assets from enterprise IT and restrict access by function.
• Use MFA and role-based access: Ensure only authorized personnel can make changes or access sensitive systems.
• Allow-list critical software only: Block all unapproved applications or services by default.
• Monitor ICS traffic for anomalies: Use OT-aware tools to detect unusual commands or device behavior.
• Stay current on patches: Regularly update firmware and document system baselines for auditing and recovery.
  

Build security into ICS planning

ICS security should be part of system procurement and deployment—not an afterthought. Ask vendors about patching policies, protocol support, and compliance alignment (e.g., NIST SP 800-82 or IEC 62443). Include ICS in broader incident response plans and security governance.

How ICS supports strategic operations and resilience

Industrial control systems are more than automation tools. In today’s complex industrial environments, ICS platforms play a central role in driving operational continuity, reducing risk, and enabling data-driven decision-making across the enterprise.

For leadership teams evaluating system upgrades or new implementations, here’s how ICS investments translate into broader business outcomes:

• Increase operational uptime and system visibility. ICS platforms centralize monitoring and control, allowing teams to respond faster to faults and reduce unplanned downtime. Remote visibility through SCADA systems also limits the need for manual inspections, especially in geographically dispersed sites.
  
  
• Strengthen regulatory compliance and audit readiness. Many industries, such as energy, pharmaceuticals, and water utilities, operate under strict environmental and safety regulations. ICS platforms provide timestamped logs, alarm histories, and secure access trails that support regulatory reporting and third-party audits.
• Improve cross-functional coordination. The data collected by ICS systems is valuable well beyond the production floor. Supply chain teams use it to adjust inventory needs in real time. Engineering teams analyze trends to improve yield. IT teams integrate ICS telemetry into broader dashboards for enterprise monitoring.
• Enable long-term digital transformation. Modern ICS architectures support phased upgrades, cloud integrations, and analytics platforms that unlock predictive maintenance, process optimization, and AI-driven forecasting. This positions organizations to scale with agility while protecting their critical infrastructure.

Proving ROI: How industrial control systems deliver business value

Industrial control systems are often seen as a technical upgrade, but their real value comes from measurable business impact. For operations and executive leaders seeking proof that ICS investments pay off, there are three main areas where ROI can be tracked: efficiency, downtime reduction, and cost control.

Use efficiency metrics to benchmark improvements

The most immediate ROI indicator is operational efficiency. By automating manual processes and improving real-time visibility, ICS deployments help teams reduce waste, improve asset utilization, and streamline workflows.

Key metrics to track:

• Overall equipment effectiveness (OEE): Use ICS data to calculate uptime, speed losses, and quality rates
• Mean time to repair (MTTR): ICS alerts help teams isolate faults faster and reduce maintenance delays
• Cycle time consistency: Automation through PLCs ensures repeatable performance across shifts or locations

Quantify downtime savings and asset reliability

Unplanned downtime is one of the most expensive threats to industrial operations. ICS platforms help predict and prevent system failures by continuously monitoring sensor data, flagging anomalies, and automating shutdown or failover routines.

How to measure impact:

• Compare downtime hours per quarter before and after ICS implementation
• Monitor first-pass yield rates to see how much rework is avoided
• Track asset longevity improvements from proactive maintenance alerts

According to the U.S. Department of Energy, predictive maintenance enabled by ICS and sensors can reduce downtime by 35% to 45%, depending on the industry.

Connect automation to labor and energy savings

Well-optimized ICS systems improve labor costs and energy usage. For example, replacing manual inspections with automated sensor networks or automating nighttime operations can reduce headcount strain and electricity consumption.

Cost-related indicators to review:

• Labor hours per production unit
• Energy consumed per unit output
• Number of site visits required for remote assets (especially in oil, gas, and utilities)

Practical tip: When budgeting for ICS, consider indirect savings such as fewer compliance violations, lower insurance premiums, or reduced emergency repair costs.

Command and conquer

Investing in an industrial control system is no longer just about automating tasks—it’s about ensuring visibility, safety, and resilience in increasingly complex operations. Decision-makers should start by aligning ICS selection with their facility’s architecture, operational risk profile, and long-term digital transformation goals.

The most successful ICS projects begin with collaboration between IT and OT teams, backed by a clear implementation roadmap and ROI metrics. Whether you’re upgrading a legacy SCADA network or deploying a modern DCS, the right system should deliver measurable improvements in uptime, efficiency, and security posture.

As next steps, assess your current control environment, identify integration gaps, and evaluate vendors not just for features but also for implementation support, open architecture, and long-term maintenance options.

Keep your ICS better protected with network security upgrades like network detection and response software that continually monitors for security threats to your systems.