Cyberattacks on operational technology (OT) are escalating, especially across sectors like defense and manufacturing. Yet many organizations still don’t know what’s actually connected to their networks. If you can’t see the devices and systems running your operations, you can’t defend them or show that you’re meeting standards like CMMC or NIST 800-82.
This lack of visibility is a problem with real consequences. Nearly half of the organizations in a recent study reported that OT cyber intrusions disrupted production, and 42% attributed these attacks to lost revenue. To get on top of the situation, your organization needs an OT asset inventory. It’s an ongoing process of identifying, classifying, and maintaining visibility into the devices and systems that run your operational environment.
However, many organizations still lack the structure or resources to maintain an accurate, living inventory over time. An experienced outside consultant who combines strategy and execution to support the necessary technical work is often required. If you’re ready to start building a mature OT asset inventory program from the ground up, here are seven tips to help you do it right.
Operational-technology (OT) assets are the hardware, software, and network components that monitor, control, or directly support physical processes in industrial or mission-critical environments. Unlike conventional IT endpoints such as laptops or servers, OT assets typically reside in manufacturing lines, utilities, transportation systems, defense supply chains, or medical device networks.
Common OT assets include:
OT assets anchor the physical side of modern operations. Identifying OT risks is a crucial element in building a security-first organization. If compromised, these assets can disrupt operations or lead to safety violations and noncompliance, especially in environments where availability is critical.
OT asset inventory management is the continuous process of identifying, tracking, and monitoring all OT devices and systems across your operational environment.
The process includes:
The key to building a reliable OT asset inventory is to use methods and tools that can collect device information without disrupting operations. Many OT systems run on legacy protocols and can’t tolerate active network scans, so traditional IT asset tools often fall short unless they are configured for OT-safe discovery.
It’s best to use modern OT asset inventory platforms that passively observe traffic and pull device details without causing interruptions. CISA’s guidance highlights this visibility layer as an early step toward a defensible OT architecture.
Manufacturing lines, industrial control systems, utilities, defense production, and building automation systems all fall under OT asset-inventory needs. If those systems connect to a network, even indirectly through an MSP, they must be visible in the inventory.
A thorough OT asset inventory offers many benefits, including:
Many control networks often cannot tolerate active probing because it can interfere with controller operations. Passive collection lets you extract those important asset and communication details from regular traffic without interrupting production.
After collecting the baseline data, review it with your engineering teams to verify device status and confirm network addresses. Remove entries for equipment that has been replaced, disconnected, or left idle, and flag any unknown devices for investigation.
Some devices can halt a line or affect safety if they fail, while others mainly support monitoring or record-keeping. Clear tiering helps direct monitoring and patching efforts toward the systems that are key to production continuity or regulatory exposure.
OT environments constantly change as older devices are swapped out and new hardware appears on the network. Without continuous updates, your OT asset inventory becomes outdated quickly. Continuous monitoring can capture changes, such as altered configurations or mismatched firmware versions, in near real-time.
Visibility alone doesn’t show how risk moves through the environment. You need to understand those connections to see how a failure or intrusion might spread. Network flow analytics and communication logs can reveal these interaction paths:
Every OT asset record should support compliance. When a control asks who manages an industrial workstation or what firmware runs on a PLC, the answers should already exist in the inventory. It provides auditors and security teams with a single, trusted source of truth, eliminating the need for disconnected lists that must be rebuilt manually at review time.
Vistrada helps organizations formalize this structure by linking technical inventory data to governance and evidence requirements, making compliance tracking an integral part of everyday operations.
Accurate technical details link the OT asset inventory to vulnerability and lifecycle management. Any deviation from supported versions or expected configurations can indicate a potential vulnerability. When the data is current, you can address the exposure instead of discovering it during an audit or incident.
The value of an OT asset inventory is only realized when the information is kept current and actively used. Hiring a vCISO (virtual Chief Information Security Officer) can provide the discipline needed to interpret that data and guide decisions that are aligned with operational goals.
How to do it:
Vistrada’s team-based vCISO model combines strategic oversight with hands-on implementation support. That includes establishing asset ownership structures, defining update and validation cycles, integrating inventory data into existing monitoring and ticketing systems, and aligning reporting with frameworks such as CMMC and NIST SP 800-82.
For organizations with industrial or infrastructure systems, a comprehensive OT inventory is the starting point for effective security against threats. An asset inventory gives teams a clear view of which OT assets and network connections exist and how they are changing, so they can see risk forming before incidents occur.
However, many organizations lack the capacity and cross-disciplinary expertise to keep an OT asset inventory current and audit-ready. Vistrada helps organizations implement OT asset inventory programs that satisfy security and compliance objectives by combining a team-based vCISO model with hands-on technical execution and framework alignment. This approach turns the inventory into a living program that informs decisions and reduces audit friction while supporting safe operations.
Contact Vistrada to assess your current OT asset inventory and discover how improved visibility can benefit you.