ISA/IEC 62443 is explicitly lifecycle-based, requiring cybersecurity considerations to be integrated across all phases of an automation solution’s lifecycle. This includes concept, design, implementation, verification, operation, maintenance, and decommissioning.

Step 1: Lifecycle philosophy of ISA/IEC 62443

The standard recognizes that cybersecurity risks emerge and evolve throughout the system lifecycle. Addressing security in only one phase leaves gaps that attackers can exploit.

Step 2: Design and implementation are not sufficient

While secure architecture and configuration are critical, they must be supported by secure development practices, verification, operational procedures, incident response, patching, and change management.

Step 3: Operational importance

Many cybersecurity failures occur during operation due to poor maintenance, weak access control, or unmanaged changes. ISA/IEC 62443-2-1 and 3-3 explicitly address these phases.

Step 4: End-of-life considerations

Decommissioning must also be planned to ensure data, credentials, and access paths are securely removed.

Because the standard spans management (2-x), system (3-x), and component (4-x) requirements across the lifecycle, all phases must be integrated.