System

{{entity:Cybersecurity Operations Centre}} {{hex:40A57AD9}} — final review (Flow E) of the complete system decomposition. The project entered this session in validated status with 54 requirements, 50 trace links, 2 diagrams, and 4 verification entries across 6 documents. 9 subsystems classified in the SE:cybersec-ops-centre namespace, 17,455 entities in the global graph.

Findings

Coherence: The SIEM-centric hub-and-spoke architecture is internally consistent. The {{entity:SIEM Engine}} {{hex:51F77B19}} functions as the correlation backbone with 7 specialised subsystems feeding telemetry inward and the {{entity:SOAR Platform}} {{hex:51B77B19}} driving response outward. No functional overlaps between subsystems — each owns a distinct detection or response domain. The {{entity:Communications and Reporting Subsystem}} {{hex:40A57B58}} and {{entity:SOC Facility Infrastructure}} {{hex:DE851018}} provide support without duplicating operational subsystem functions.

Completeness gaps identified: 7 of 18 system requirements lacked downward trace links to subsystem or interface requirements. Most critically: {{sys:SYS-SYS-DETECT-013}} (threat hunting), {{sys:SYS-SYS-DETECT-014}} (alert suppression), {{sys:SYS-REQS-017}} (degraded-mode detection), and {{sys:SYS-SYS-INFRA-016}} (disaster recovery) described capabilities with no implementing subsystem requirements. Verification coverage was thin — only 4 VER entries and 5 trace links covering 23 SUB+IFC requirements (22% trace coverage to verification).

Plausibility: Performance values are realistic throughout. 150K EPS ingestion, 120-second correlation, 30-second endpoint isolation, 72-hour UPS autonomy, and 10 Gbps packet capture all align with industry benchmarks for a 50,000-endpoint enterprise SOC. Interface protocols (CEF/ECS, STIX/TAXII 2.1, REST APIs) match current industry practice. The Jaccard similarity cluster at 89-95% among {{entity:Vulnerability Management System}} {{hex:41F77B19}}, {{entity:SIEM Engine}}, and {{entity:Endpoint Detection and Response Subsystem}} {{hex:51F77B19}} reflects genuine ontological similarity — these are all active, powered, software-intensive security processing systems.

Proportionality: The SIEM Engine carries the deepest decomposition (5 SUB reqs after corrections), appropriate given its role as the architectural centrepiece. The SOAR Platform has 3 SUB reqs including the new degraded-mode bypass. Support subsystems (Comms, Facility) each have 1 requirement — proportionate to their complexity. The 2 lint findings are structural observations (VER mixed with functional reqs, ontological ambiguity between SOC and authenticated API classification) rather than defects.

Corrections

Created 4 new subsystem requirements closing the untraced SYS requirement gaps:

• {{sub:SUB-SUB-SIEM-001}}: SIEM threat hunting query capability (from {{sys:SYS-SYS-DETECT-013}})
• {{sub:SUB-SUB-SIEM-002}}: Alert suppression, deduplication, and correlation grouping (from {{sys:SYS-SYS-DETECT-014}})
• {{sub:SUB-SUB-SOAR-003}}: Degraded-mode detection via direct EDR/NSM/IAM alert bypass (from {{sys:SYS-REQS-017}})
• {{sub:SUB-SUB-INFRA-004}}: SOC disaster recovery with secondary site and RTO/RPO targets (from {{sys:SYS-SYS-INFRA-016}})

Created 3 new verification entries expanding coverage from 4 to 7 VER requirements:

• VER-VER-METH-005: Response pipeline containment verification (EDR + SOAR + interface)
• VER-VER-METH-006: Network and identity monitoring sensor coverage and UEBA accuracy audits
• VER-VER-METH-007: TIP feed ingestion health checks and enrichment accuracy tests

Created 14 new trace links: 4 SYS→SUB (closing decomposition gaps), 7 SUB/IFC→VER (closing verification coverage), 3 new-SUB→VER (connecting new requirements to verification). Total trace links: 50→64.

Residual

Three system requirements remain without downward traces, all defensible as system-level constraints: {{sys:SYS-SYS-INFRA-008}} (99.95% availability — a system KPI validated by failover exercises, not a decomposable function), {{sys:SYS-SYS-INFRA-015}} (TLS 1.3 encryption — a cross-cutting policy applied uniformly to all interfaces), and {{sys:SYS-REQS-018}} (minimum analyst staffing — an operational management requirement outside technical decomposition scope). The lint finding about VER requirements mixed with functional requirements is a structural convention, not a defect. {{ifc:ARC-ARC-RAT-001}} remains an orphan by design — architecture decisions document rationale, not traceable requirements.

Verdict

Pass. The {{entity:Cybersecurity Operations Centre}} decomposition is coherent, complete, plausible, and proportionate. A security architect or CISO would recognise this as a credible SOC architecture suitable for beginning detailed design. Baseline COMPLETE-2026-03-18 created. Status set to complete. Project cleared from active work queue.

flowchart TB
  SOC["Cybersecurity Operations Centre"]
  SIEM["SIEM Engine"]
  NSM["Network Security Monitoring"]
  EDR["Endpoint Detection and Response"]
  TIP["Threat Intelligence Platform"]
  VMS["Vulnerability Management"]
  SOAR["SOAR Platform"]
  IAM["Identity and Access Monitoring"]
  INFRA["SOC Facility Infrastructure"]
  COMMS["Communications and Reporting"]
  NSM -->|IDS alerts, DNS, NetFlow| SIEM
  EDR -->|Endpoint telemetry| SIEM
  TIP -->|IOC watchlists| SIEM
  IAM -->|Auth events, UEBA alerts| SIEM
  VMS -->|Vuln scan results| SIEM
  SIEM -->|Correlated alert packages| SOAR
  SOAR -->|Containment commands| EDR
  SOAR -->|Network containment| NSM
  TIP -->|Enrichment API| SOAR
  SOAR -->|Incident data, reports| COMMS
  SIEM -->|Operational metrics| COMMS