What Good OT Asset Discovery Reporting Looks Like

OT asset discovery is only useful if the results can be understood, trusted, and acted on. The reporting is where discovery either becomes operationally valuable or remains a technical exercise.

Good OT asset discovery reporting translates raw observations into a clear picture of what exists, how it connects, and why it matters. It supports security, operations, and risk decisions without overwhelming the reader or introducing unnecessary complexity.

This article outlines the core components of effective OT asset discovery reporting and the common mistakes that reduce its value.

Usable asset inventories

An asset inventory is the foundation of OT asset discovery reporting. However, usefulness depends less on volume and more on structure and clarity.

A good OT asset inventory should be:

• Clearly scoped to OT and industrial systems
• Structured in a way that supports filtering and grouping
• Consistent in naming and classification

Typical fields include:

• Asset name or identifier
• Asset type (PLC, HMI, safety system, sensor, gateway, etc.)
• Vendor and model
• Firmware or software version (where observable)
• Network location (IP, VLAN, zone)
• Operational role or function

In real environments, inventories are most effective when they distinguish clearly between IT-managed systems and OT-owned assets, even when they share network infrastructure.

Inventories should be provided in formats that teams can reuse, such as spreadsheets or structured exports, rather than static screenshots or PDFs alone.

Network and communication maps

Asset lists show what exists. Network and communication maps show how assets interact.

Good OT asset discovery reporting includes visual or tabular representations of:

• Network zones and segments
• Key communication paths between systems
• Protocols in use (for example Modbus, DNP3, EtherNet/IP)
• Interfaces between OT and IT or external networks

These maps should reflect observed communication rather than assumed design diagrams. In operational environments, documented architectures often differ from what is actually deployed or actively communicating.

Effective maps prioritise clarity over completeness. The goal is to make relationships and dependencies understandable, not to document every packet flow.

Where possible, communication maps should align with recognised OT models such as zones and conduits, even if the environment does not fully implement them.

Risk-oriented summaries

Raw discovery data does not automatically translate into risk understanding. Good reporting bridges that gap without turning into a vulnerability assessment.

A risk-oriented summary typically highlights:

• Unsupported or end-of-life devices
• Assets with insecure or legacy protocols
• Unexpected connectivity paths
• High-consequence systems with broad network exposure

Rather than assigning scores or making remediation demands, effective summaries explain why certain observations matter. For example, identifying a safety controller communicating outside its expected zone provides context without prescribing solutions.

It is common to see greater engagement when risk summaries are framed in terms of operational impact and exposure, rather than compliance or theoretical threat models.

These summaries are often the most widely read section of the report and should be written for non-specialist stakeholders as well as technical teams.

Reporting mistakes to avoid

Several common issues reduce the practical value of OT asset discovery reporting.

Overly technical outputs

Reports that rely heavily on tool-generated tables, raw logs, or protocol dumps can be difficult to interpret. Technical detail should be available, but not at the expense of clarity.

No clear scope definition

Without a clear statement of what was and was not included, readers may assume full coverage where it does not exist. This can lead to misplaced confidence in the results.

Asset lists without context

Inventories that lack operational role, ownership, or network placement provide limited value. Assets need context to support decision-making.

Risk language without explanation

Flagging issues as “high risk” without explaining why can undermine trust in the report. Observations should be clearly linked to operational or security relevance.

Static, one-off reporting

Discovery reports that are treated as snapshots often become outdated quickly. While not every report needs to address ongoing visibility, good reporting acknowledges that environments change over time.

Bringing it together

Good OT asset discovery reporting is structured, readable, and grounded in observed reality. It enables teams to understand what is present, how systems interact, and where attention may be needed.

The most effective reports balance technical accuracy with operational relevance, allowing both engineers and decision-makers to use the findings confidently.

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