RWS Specification Accepted — 272 Requirements Across 8 Subsystems Pass Final Review
System
{{entity:Remote Weapon Station (RWS)}} final review session covering the complete concept-level specification: 272 requirements (17 STK, 18 SYS, 84 SUB, 29 IFC, 111 VER, 13 ARC), 275 trace links, 10 diagrams, 84 classified entities across 8 subsystems. The system entered review in qc-reviewed state following validation in sessions 637–638.
Coherence
The decomposition partitions cleanly into eight subsystems with no overlapping responsibilities: {{entity:Fire Control System}} (FCC, TTP, BCM, WCI — 34 SUB requirements), {{entity:Safety Interlock System}} (DCSC, HFIR, E-stop, arming key — 19 SUB), {{entity:Turret Drive Assembly}} (7 SUB), {{entity:Communications Interface Unit}} (7 SUB), {{entity:Electro-Optical Sensor Assembly}} (5 SUB), {{entity:Power Distribution Unit}} (5 SUB), {{entity:Weapon and Ammunition Handling Assembly}} (3 SUB), and {{entity:Operator Control Unit}} (2 SUB). The requirement depth is proportionate — FCS and SIS carry the most requirements as the highest-complexity and highest-criticality subsystems respectively. Architecture decisions (ARC-REQ-001 through ARC-REQ-013) are mutually consistent: the separated SIS/FCS safety architecture, 1oo2D redundancy for the {{entity:Dual-Channel Safety Controller}}, and fail-safe weapon interlocks form a coherent safety concept.
flowchart TB
n0["Remote Weapon Station (RWS)"]
n1["EOSA"]
n2["FCS"]
n3["TDA"]
n4["OCU"]
n5["SIS"]
n6["WAHA"]
n7["PDU"]
n8["CIU"]
n1 -->|Sensor video, target data| n2
n2 -->|Servo commands| n3
n2 -->|Fire request, arm status| n5
n5 -->|Fire enable/inhibit| n6
n5 -->|Drive enable, brake cmd| n3
n4 -->|Operator commands| n2
n2 -->|Display data, video| n4
n4 -->|E-STOP, arm/safe| n5
n7 -->|28V/12V/5V power| n1
n7 -->|12V/5V power| n2
n7 -->|28V drive power| n3
n8 -->|GPS, BMS data| n2
n2 -->|Video, status| n8
Completeness
Full trace chain coverage: all 17 STK requirements trace to SYS, all 18 SYS trace to SUB or IFC, and 111 VER requirements cover the subsystem and interface specifications. Zero orphan requirements. Five ConOps scenarios were validated in sessions 637–638 with gaps addressed: Urban Patrol Engagement ({{ver:VER-REQ-109}}), Emergency Stop ({{ver:VER-REQ-106}}, {{ver:VER-REQ-107}}), IED Strike link-loss ({{ver:VER-REQ-107}}), Field Maintenance ({{ver:VER-REQ-115}}), and Degraded Sensor Operation ({{ver:VER-REQ-117}}). The sole residual gap — {{sub:SUB-REQ-078}} (optical-to-thermal failover) lacking verification — was closed in this session.
Acceptance Assessment
Procurement: A procurement authority could issue a contract from this specification. Performance requirements are quantified (first-round hit probability ≥0.5 at 1500m, 8s detection-to-fire, 360° azimuth at 60°/s, 1200-hour MTBF). Safety requirements cite IEC 61508 (Functional safety of E/E/PE safety-related systems) and specify SIL-appropriate architectures. Environmental requirements reference MIL-STD-810H, MIL-STD-461G (Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment), and IP67 per IEC 60529.
Test programme: The 111 VER requirements specify test setups, measurement methods, pass criteria, and trial counts. A test organisation could write procedures directly from VER text without additional interpretation.
Safety argument: {{entity:Safety Interlock System}} implements {{trait:Normative}} 1oo2D architecture with hardware interlock relay, arming key, and E-stop. The chain from hazard identification through SIL allocation ({{stk:STK-REQ-015}}) to safety requirements (SIS subsystem) to verification is complete and traceable. Safe states are defined for all fault modes.
Per-Subsystem Summary
| Subsystem | SUB | IFC | VER | Diagrams |
|---|---|---|---|---|
| Fire Control System | 34 | 8 | ~35 | 1 |
| Safety Interlock System | 19 | 6 | ~20 | 1 |
| Turret Drive Assembly | 7 | 3 | ~10 | 1 |
| Communications Interface Unit | 7 | 4 | ~8 | 1 |
| Electro-Optical Sensor Assembly | 5 | 3 | ~8 | 1 |
| Power Distribution Unit | 5 | 2 | ~7 | 1 |
| Weapon and Ammo Handling | 3 | 3 | ~6 | 1 |
| Operator Control Unit | 2 | 2 | ~4 | 1 |
Cross-Domain Insights
UHT classification reveals high Jaccard similarity (93%) between {{entity:Hardware Firing Interlock Relay}} {{hex:D6F51019}} and {{entity:channel safety controller}} {{hex:D6F51018}}, consistent with their co-location in the SIS safety chain. The {{entity:Ballistic Computation Module}} {{hex:41F73B19}} shares {{trait:Normative}} classification, reflecting its role enforcing firing table integrity constraints — an ontological insight that justified SUB-REQ-059 (firing table CRC validation).
Corrections
Deleted 7 duplicate VER entries: VER-REQ-023, VER-REQ-029 (duplicates of VER-100 for {{ifc:IFC-REQ-025}}); VER-REQ-028, VER-REQ-030 (duplicates of VER-REQ-024 for {{ifc:IFC-REQ-027}}); VER-REQ-050 (duplicate of VER-REQ-046 for {{sub:SUB-REQ-055}}); VER-REQ-055 (duplicate of VER-REQ-056 for {{sub:SUB-REQ-060}}); VER-REQ-102 (duplicate of VER-REQ-098 for {{sub:SUB-REQ-073}}). Reassigned 1 homeless VER (VER-REQ-068) to verification-requirements document. Created VER for previously unverified {{sub:SUB-REQ-078}} (EOSA optical-to-thermal failover).
Efficiency
The RWS specification was completed across approximately 12 sessions: concept (1), scaffold (1), decomposition (5–6 for 8 subsystems), QC (2), validation (2), and this review session. No sessions were wasted — QC sessions identified genuine issues (duplicate VERs accumulated across decomposition sessions) and validation closed real gaps in system-level test coverage.
Residual
60 medium-severity lint findings remain, all ontological mismatches (Physical Medium without material property requirements, System-Essential without explicit redundancy requirements, Human-Interactive without dedicated HMI requirements). These are appropriate for detailed design, not concept-level specification: material properties are partially addressed by environmental specs (IP67, MIL-STD-810H temperature), redundancy is addressed architecturally (SIS 1oo2D, FCC watchdog), and HMI is covered by OCU display/controller requirements. The OCU subsystem has only 2 SUB requirements — acceptable at concept level but should expand significantly in detailed design to cover ergonomics, display symbology, and operator workload.
Verdict
Pass. The Remote Weapon Station specification is coherent (clean subsystem partition, consistent architecture decisions), complete (full STK→SYS→SUB→IFC→VER trace chain, all 5 ConOps scenarios validated), proportionate (safety-critical subsystems have deeper requirements), and would support procurement, test programme development, and safety authority review. Baselined as COMPLETE-2026-03-27.