← Home

Cybersecurity Acceptance Testing

The cybersecurity of an Automation Solution should be tested and accepted by the operating organisation before delivery and startup. Cybersecurity acceptance testing confirms that implemented controls match the agreed cybersecurity requirements and that the system is sufficiently robust against known weaknesses — typically through Cybersecurity Factory Acceptance Testing (CFAT) and Cybersecurity Site Acceptance Testing (CSAT).

Teaching note: Paraphrased for learning from IACS cybersecurity course material and ISA/IEC 62443 practice. Not a substitute for project procedures, contractual acceptance criteria, or the normative text of ISA/IEC 62443.

Related: IEC 62443-2-2 Automation Solution Security Lifecycle | CRS (ZCR 6) | IEC 62443-2-4 Service Providers | IEC 62443-4-1 SVV | System Hardening | Network Discovery and Scanning | IACS Cybersecurity Roles


Standards map

Source Role for CFAT / CSAT
ISA/IEC 62443-2-2 Phase 4 – Verification & Validation Primary home — Automation Solution V&V; FAT/SAT (including cybersecurity acceptance) against the CRS
ISA/IEC 62443-3-2 CRS (ZCR 6) Input — specifications and constraints being verified
ISA/IEC 62443-2-4 Supporting — service-provider security programme capabilities that enable sound integration and V&V delivery. Programme evaluation/certification (TR/TS 62443-6-1) is not a substitute for project CFAT/CSAT
ISA/IEC 62443-4-1 SVV Related, different scope — product-supplier development testing; techniques overlap, object does not

CFAT vs CSAT

Cybersecurity Factory Acceptance Testing (CFAT)

Performed at the factory (or integrator facility), typically by the vendor or system integrator. Best run after functional factory testing of the system is complete, so the security baseline is checked on a working build.

Cybersecurity Site Acceptance Testing (CSAT)

Performed onsite where the system will operate. Run after operational/site testing is complete and before release to operations, with the system in a locked-down state ready for production use.

Test order: Run cybersecurity acceptance testing after the relevant functional testing (factory then site). CFAT follows functional FAT; CSAT follows operational/site testing and precedes release to operations. Do not schedule cyber tests before the functional build is stable — you would be validating security on a moving target.
Validated / high-change-control sectors (for example nuclear or pharmaceutical) often treat cybersecurity acceptance as integral to functional FAT and SAT rather than as a fully separate campaign. Align timing with the project’s change-management and quality system — do not invent a conflicting sequence.

Two objectives

1. Verification of cybersecurity specifications

Confirm that policies, configurations and security components work as intended. Typical scope includes:

Use the Cybersecurity Requirements Specification (CRS) and hardening baselines (see System Hardening) as the expected state.

2. Cybersecurity robustness testing

Test the design to discover weaknesses: resilience to attack, intrusion testing against firewall configuration, and scans for known vulnerabilities. The goal is to find issues before an external party does — under controlled, authorised conditions.

Use careful OT-safe methods; aggressive scanning can disrupt control systems. See Network Discovery and Scanning and prefer lab/FAT windows or scheduled outages for higher-risk techniques.


Best practices


Tooling (categories)

Projects commonly use:

Prefer categories and approved project toolsets over chasing product names. Check vendors and national guidance for acceptance-testing recommendations applicable to your sector.


Key takeaways