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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
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.
Risk assessment relevance: Periodic backups of device state, configuration,
recipes and control data support faster recovery and often lower impact in residual risk
scoring when verified.
See
SP and Risk Assessment.
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.
Practice notes (backup-in-depth)
- Use layered backups (local / facility / disaster) with time sequencing so recent local
copies support fast recovery and offline copies survive ransomware that targets online
backup stores.
- Include configurations for PLCs, HMIs, switches, firewalls and databases — not only
Windows images.
- Store backups onsite and offsite; encrypt confidential media; define secure media disposal.
- Test restore regularly against realistic recovery-time expectations; keep backup systems
patched to a comparable level as production where they support failover.
- Assign clear responsibility for backup and restore; update the plan when architecture or
contacts change.
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.