How to Secure Remote Maintenance in Smart Factories

Many manufacturers rely on remote maintenance in smart factories to diagnose equipment problems and reduce downtime. However, these connections can also expose systems to new security risks. Understanding the main vulnerabilities of this setup can help manufacturers implement practical ways to secure remote maintenance in smart factories without disrupting operations.

The IT and OT Convergence Challenge

Remote maintenance allows authorized technicians, engineers or vendors to inspect, diagnose and support factory equipment from outside the facility through a secured network connection. In a smart factory, this often involves connecting to industrial control systems and monitoring platforms or machine interfaces to review performance data, identify faults, adjust configurations and guide repairs without requiring an on-site visit.

Operational technology (OT) environments historically operated with little connection to corporate IT networks. Modern smart factories have changed that model. Production equipment now exchanges data with enterprise applications, cloud services, monitoring platforms and other connected systems.

That connectivity creates different priorities for IT and OT departments. IT teams focus heavily on automation, data protection and access controls, while OT employees handle equipment availability and worker safety. Industrial systems may also have long service lives and technical limitations that make conventional security controls challenging to deploy.

Traditional perimeter defenses provide less protection when industrial systems communicate with networks and users outside the factory. According to the Cybersecurity and Infrastructure Security Agency, zero-trust principles can help organizations account for the distinct security and operational requirements of industrial environments.

Remote maintenance in smart factories adds another connection that security teams need to control. Engineers, equipment manufacturers, contractors and other service providers may require access from outside the facility, creating additional pathways into OT systems.

Why Remote Maintenance in Smart Factories Expands the Threat Landscape

Remote maintenance can shorten response times and reduce the need for technicians to travel to a facility. It also introduces risks involving legacy equipment, remote endpoints, credentials and third-party access.

Vulnerabilities in Legacy Equipment

Many factories still depend on older industrial control systems, programmable logic controllers (PLCs), supervisory control and data acquisition systems (SCADAs), and other equipment designed before modern connected environments became commonplace.

Replacing this equipment can require major investment and extended production disruptions. Some machines also support processes that cannot easily stop for routine patching. Software updates may affect compatibility with other components, while older devices may lack support for modern authentication or security tools.

Carnegie Mellon University’s Software Engineering Institute notes that industrial environments often contain legacy devices with limited security capabilities. OT teams also have to consider safety and availability when introducing new security controls.

The Risks of Off-Site Access

Remote maintenance also introduces risks through the people and devices connecting to factory systems. A technician may work from a corporate office or at home, while equipment vendors may require temporary access to specialized machinery.

Compromised credentials can grant an attacker access to production systems. An infected laptop can enable another route into the environment. Vendor accounts can create additional exposure when organizations leave permissions active after a maintenance task ends.

The shift toward remote work also demonstrates how changes in working arrangements can affect cybersecurity. A survey found that 23% of respondents reported an increase in cybersecurity incidents after employees began working from home.

In a factory, a compromised remote connection can affect physical operations as well as information systems. Unauthorized access could interfere with production controls or processes that affect worker safety.

Top Strategies to Secure Remote Maintenance in Smart Factories

Manufacturers can protect remote maintenance by controlling who connects, what they can reach and how long that permission lasts. Several layers of access control can limit the damage from a compromised account or device.

Implement Zero-Trust Architecture

Zero-trust architecture requires organizations to verify access requests based on identity, device status, authorization and other relevant conditions. A user or device does not receive broad access simply because it connects from a familiar network.

For remote maintenance, this means a technician should receive access only to the systems required for a particular task. If an attacker gains control of that person’s credentials, limited permissions can restrict access to other parts of the factory network.

Manufacturers can apply zero-trust principles through several practical measures, such as:

• Stronger authentication
• Limited privileges
• Separate network zones
• Session monitoring
• Regular access permissions reviews

Industrial control systems present special challenges because many devices lack modern security features. A phased rollout can help teams address the highest-risk systems first. Security and engineering teams should identify which assets require remote support and determine the minimum access needed for each maintenance task.

Enforce Strict Network Segmentation

Manufacturers should separate corporate IT networks from OT environments and divide critical production systems into smaller zones where appropriate. Segmentation limits the routes that an intruder can use after gaining access to one part of the environment.

Microsegmentation can restrict communication between individual systems and allow only approved traffic. For example, a compromised corporate workstation should have no automatic route to a PLC or industrial control server.

Reducing the affected radius through zero trust and OT segmentation can protect production continuity and worker safety. This process includes separating sensitive OT assets and limiting communication paths that cross network boundaries.

Utilize Jump Servers for Mediated Access

A jump server provides a controlled intermediary between a remote user and the OT environment. The technician connects to the server first, then reaches an approved machine through that controlled connection.

This setup gives security teams a central point for authentication, authorization, logging and session monitoring. It also keeps external users from connecting directly to production equipment.

Require Identity-Based Authentication

Strong authentication is the last line of defense once a connection request reaches the network. Multifactor authentication should be mandatory for every remote maintenance session. It includes pairing a password or other knowledge-based factor with something else, such as a physical token, authentication app or biometric check. That way, stolen passwords alone can’t grant access.

Role-based access controls narrow that access further by ensuring each user can only reach the specific systems their job requires. Methods include:

• Assigning permissions by role and task, not by departmentwide default.
• Setting access to expire automatically at the end of a maintenance window.
• Requiring a second verification factor for any session touching production controls.
• Reviewing and revoking vendor credentials regularly.

Aligning Cybersecurity With Operational Uptime

Securing remote maintenance in smart factories requires careful control over who can access factory systems, what they can reach and when they can connect. IT and OT teams can reduce risk by combining zero-trust principles, network segmentation, multifactor authentication and more while prioritizing production needs.