IEC PAS 63325:2020

Overview - IEC PAS 63325:2020 (Lifecycle requirements for functional safety and security for IACS)

IEC PAS 63325:2020 is a Publicly Available Specification from IEC that provides requirements and guidance to coordinate functional safety and cybersecurity across the lifecycle of Industrial Automation and Control Systems (IACS). Targeting IACS (including the Equipment Under Control - EUC - and safety‑related systems), the PAS does not define a new lifecycle; instead it aligns established functional safety and security lifecycles to avoid conflicts between safety measures and security countermeasures and to ensure risk reduction objectives are met.

Key topics and technical requirements

• Lifecycle stages covered: concept & scope, risk assessment, development & implementation, operation & maintenance, decommissioning.
• Risk coordination: integration of hazard/risk analysis with threat‑vulnerability assessment to identify combined safety and security risks and to establish risk criteria.
• Conflict resolution: guidance for identifying and resolving situations where security controls could impede safety function performance (or vice versa).
• Management coordination: organizational requirements, management of change and technical management processes to sustain coordinated safety and security throughout lifecycle phases.
• Operational resilience: requirements for responses to system failures or security events, monitoring, routine maintenance and modification controls.
• Practical measures (informative): examples include segmentation (zones and perimeter), access and remote access controls, device‑ and control‑level protections, integration of safety and security monitoring, and physical compensation measures - as illustrated in Annex A.

Practical applications and who will use it

IEC PAS 63325 is practical for organizations and professionals involved with industrial control systems who must integrate safety and cybersecurity workstreams:

• Safety engineers and security engineers coordinating requirements and tests
• Control system designers and system integrators implementing safe and secure architectures
• Asset owners / operators defining lifecycle processes and maintenance practices
• Project managers and change control teams managing organizational and technical change
• Standards and compliance officers aligning IEC 61508 / IEC 62443 practices on a project level

Use cases include early lifecycle risk assessments, designing compatible safety/security architectures, preparing operational procedures to avoid safety/security conflicts, and managing changes that affect safety integrity levels (SIL) or security posture.

Related standards

• IEC 61508 (functional safety fundamentals and SIL)
• IEC 62443 series (industrial cybersecurity)
• IEC TR 63069 (framework recommendations for combining functional safety and security)

IEC PAS 63325 is a concise, lifecycle‑focused resource to help make IACS systems both safe and secure by design while minimizing costly rework from conflicting controls.