IEC 62443-2-1 Clause 13 – System Integrity and Availability

ISA/IEC 62443-2-1:2024, Clause 13 covers system integrity and availability as Security Program Element SPE 8 in the asset owner’s IACS Security Program.

SPE 8 keeps the plant able to run as intended and recover when something goes wrong — through continuity planning, resource resilience, defined failure behaviour, and reliable backup and restore.

Teaching note: The summaries below paraphrase ISA/IEC 62443-2-1:2024 for learning purposes. They are not a verbatim extract of the standard — always refer to the published text for normative wording and assessment.

Reference: ISA/IEC 62443-2-1:2024, Clause 13
Related: Security Program Requirements (2024) | CSMS (2010)

SPE pages: SPE 1 | SPE 2 | SPE 3 | SPE 4 | SPE 5 | SPE 6 | SPE 7 | SPE 8

Requirements in this SPE

AVAIL 1.1 – Continuity management (Clause 13.2.1)
AVAIL 1.2 – Resource availability management (Clause 13.2.2)
AVAIL 1.3 – Failure-state (Clause 13.2.3)
AVAIL 2.1 – Backup (Clause 13.3.1)
AVAIL 2.2 – Backup non-interference (Clause 13.3.2)
AVAIL 2.3 – Backup verification (Clause 13.3.3)
AVAIL 2.4 – Backup media (Clause 13.3.4)
AVAIL 2.5 – Backup restoration (Clause 13.3.5)

AVAIL 1 – System availability and intended functionality

Reference: ISA/IEC 62443-2-1, Clause 13.2

AVAIL 1.1: Continuity management

Clause: 13.2.1

Summary
A current disaster recovery plan, business continuity plan, or both, shall cover credible disruption scenarios, failure handling and how required operational continuity is maintained.

AVAIL 1.2: Resource availability management

Clause: 13.2.2

Summary
The IACS shall be protected against loss of resources from power failure, unexpected load, hardware faults and denial-of-service attacks, with remediation options such as equipment replacement planned in.

AVAIL 1.3: Failure-state

Clause: 13.2.3

Summary
If a detected security compromise means normal operation cannot continue, the IACS shall be taken to a predetermined safe or known state.

AVAIL 2 – Backup/restore/archive

Reference: ISA/IEC 62443-2-1, Clause 13.3

AVAIL 2.1: Backup

Clause: 13.3.1

Summary
The IACS shall be backed up at regular intervals so it can be returned to a stable state.

AVAIL 2.2: Backup non-interference

Clause: 13.3.2

Summary
Backup activity shall be validated so it does not disrupt normal plant operation.

AVAIL 2.3: Backup verification

Clause: 13.3.3

Summary
Backup integrity shall be checked when the backup finishes and again at later intervals.

AVAIL 2.4: Backup media

Clause: 13.3.4

Summary
Backup media shall be handled and stored so it remains intact, authentic and available when needed, while protecting confidentiality of the data.

AVAIL 2.5: Backup restoration

Clause: 13.3.5

Summary
Processes shall restore the IACS from backup to a stable state within an acceptable time.

Key Takeaways

SPE 8 sustains intended operation and recovers from disruption or compromise.
Eight AVAIL requirements under Clause 13 cover continuity and backup/restore.
See Security Program Requirements (2024) for SP context.