Why OT Patch Management Fails - And How to Fix It

In industrial environments where uptime is king and change can carry serious consequences, patching often becomes the elephant in the room. Everyone knows it needs to be done. Few want to touch it. And many systems simply go unpatched for months, or even years, despite known vulnerabilities.

The truth is, patch management in Operational Technology (OT) isn't just a technical process; it's an operational balancing act. When handled poorly, it introduces more risk than it removes. When done well, it becomes a strategic enabler of cyber security and operational resilience.

So why do so many patch programs fail in industrial environments? And what can be done to fix them?

Let’s unpack the five most common failure points and the path forward that’s emerging from leaders in the field.

1. The Wrong Model: IT-Centric Thinking in an OT World

Traditional IT patching practices assume agility: systems that can be restarted frequently, sandboxed for testing, and updated during off-hours without major consequences. None of this applies to OT.

OT systems run 24/7, often in safety-critical roles. Many have limited vendor support, custom configurations, and no room for trial-and-error. An ill-timed or incompatible patch could shut down production, trigger safety events, or require costly rollbacks.

The Fix: Stop trying to copy-paste IT patching methods and frameworks into OT. Build an OT-native approach.

This means:

• Working with vendors to certify patches before deployment
• Testing patches in mirrored environments
• Rolling out in planned, low-risk cycles aligned with operational windows

At Dexcent, this shift begins with acknowledging that every patch decision is a risk decision and managing that risk with deliberate structure.

2. Overburdened Internal Teams

OT and SCADA teams are already stretched thin supporting operators, maintaining uptime, and addressing immediate issues. Patching, especially across complex and legacy environments, often becomes a back-burner task.

A Canadian pipeline operator that Dexcent worked with faced this exact challenge. Their internal teams were tasked with coordinating, testing, and executing patching for SCADA systems, on top of their existing workload. Patching cycles were often delayed or incomplete, despite best intentions.

The Fix: Relieve internal teams from the operational burden.

Outsourcing patching to a trusted OT-native partner allowed this operator to:

• Stick to a predictable patching schedule
• Ensure validation without overloading in-house staff
• Free up their SCADA team to focus on high-priority support

3. Lack of Process and Structure

In many environments, patching is still a reactionary process, done only when a threat feels urgent or an audit is looming. Without a standardized process, every cycle feels like a new fire drill.

Patch inventories are incomplete. Asset visibility is lacking. Changes are poorly documented, and rollback plans are unclear.

The Fix: Establish a repeatable, phased approach.

Dexcent’s model breaks the patching lifecycle into structured phases:

1. Planning and onboarding
2. Non-production deployment, implementation,  and validation
3. Production deployment, implementation,  and validation
4. Documentation and prep for the next cycle

This cadence transforms patching from an ad hoc scramble into a rhythm that builds team confidence over time.

4. Fear of Downtime and Breakage

One of the biggest reasons patching is avoided? Fear. Fear that the patch will cause systems to break, or that recovery will be slow, or that it might disrupt operations.

These fears are valid, especially in environments with outdated systems or minimal vendor support. But avoiding patching due to fear only increases exposure over time.

A North American pipeline operator working with Dexcent needed to patch thousands of assets quarterly under TSA guidelines. Missing patch deadlines could trigger compliance failures. But with no repeatable method in place, patching at that scale felt overwhelming.

The Fix: Mitigate fear with validation, automation, and rollback readiness.

By embedding Dexcent into their infrastructure team, the operator:

• Developed test and rollback protocols
• Automated large-scale deployments using Microsoft MECM
• Reserved white-glove, manual patching for high-risk systems
• Capture process for each division in patching playbooks

This hybrid model achieved over 95% compliance without disrupting operations.

5. Disconnected Stakeholders

Patching requires coordination across engineering, Cyber Security, compliance, and operations. But in many organizations, these groups operate in silos, each with different views of risk and different priorities.

Cyber Security wants fast remediation. Operations wants zero disruption. Compliance wants documentation. Engineering wants safety guarantees.

The Fix: Align around a shared process, owned by all.

A successful patching program creates shared visibility:

• What’s being patched and why
• Who is responsible at each stage
• How success is measured and documented

Dexcent facilitates this through regular touchpoints, clear roles, and transparent reporting, keeping all stakeholders aligned and informed.

Moving Forward: From Patching Pain to Predictability

OT patching fails when it’s treated like an afterthought. It succeeds when it becomes a structured process, owned collaboratively, and tailored to the realities of industrial operations.

Whether you're operating a pipeline, a refinery, or a manufacturing plant, the risks of ignoring patching are growing, and the excuses for deferring it are shrinking.

By shifting to a service-driven model like ICS Patching-as-a-Service, industrial organizations are turning what was once a source of stress into a pillar of operational resilience.

Want to see how this can work in your environment?

Download Dexcent’s free eBook: ICS Patching-as-a-Service: Transforming Risk into Operational Resilience.

It’s packed with field-tested insights, case studies, and a clear path forward.