Methodology
How tools are rated
Each tool is rated from public documentation (READMEs, product docs, trust centers, security pages) against 12 criteria, each mapped to the four principles in the joint CISA/NSA/ASD ACSC guidance.
CISA principles
| P1 | Understand AI |
| P2 | Consider AI use in the OT domain |
| P3 | Establish governance & assurance |
| P4 | Embed safety & security practices |
Checklist
| # | Criterion | 2 points if… | Principle |
|---|---|---|---|
| C1 | Actuation capability | Cannot write/actuate, or writes are clearly isolated | P2, P4 |
| C2 | Read-only by default | Write/method tools off unless explicitly enabled | P4 |
| C3 | Write guardrails | Per-tag allowlist plus value/rate limits or interlock checks | P4 |
| C4 | Human-in-the-loop approval | Critical writes need explicit human confirmation | P4 |
| C5 | Authentication | Authenticated sessions to the OT endpoint; no anonymous default | P3, P4 |
| C6 | Encryption & cert verification | Encrypted transport with server certificate verification | P4 |
| C7 | Audit logging | Every agent call/write logged durably | P3, P4 |
| C8 | Network placement | On-prem/edge/air-gapped or push/DMZ flow; no inbound IT→OT path | P2, P4 |
| C9 | Data leaving the site | No telemetry; plant data can stay on-prem | P2 |
| C10 | Fail-safe & safety independence | Fails closed; safety systems stay independent | P4 |
| C11 | Vendor security disclosure | Published security policy / PSIRT | P3 |
| C12 | Supply-chain hygiene | Versioned/signed releases; pinned installs | P3 |
Scoring
| 2 | Verified in public docs | |
| 1 | Partial or optional: off by default, or only claimed | |
| 0 | Absent or unsafe default | |
| ? | Unknown: excluded from the score and shown separately. We never guess. |
A percentage is shown only when at least 6 of 12 criteria are known; otherwise the tool is listed as Insufficient data. Ratings are re-checked periodically and on request.
Independence
Paid listings and sponsorships never change scores. Verified badges only confirm that a vendor supplied documentation we could check.