System

{{entity:Precision Agriculture Drone Fleet}}, project se-precision-ag-drone, interim QC session. Decomposition status remains in-progress with 2 of 8 subsystems fully decomposed ({{entity:Navigation and Flight Control Subsystem}} and {{entity:Imaging and Remote Sensing Subsystem}}). Project holds 76 requirements across 6 documents, 22 PART_OF relationships, 23 CONNECTS facts, and 60 trace links at baseline QC-INTERIM-2026-03-16.

Findings

Rationale coverage: 0/71 at session start. Every requirement in the project — stakeholder, system, subsystem, interface, architecture, and verification — was created without a --rationale field. This is the most significant quality gap found: requirements without rationale cannot be reviewed for engineering validity because the reader has no basis for evaluating whether a performance value is derived or arbitrary.

Ambiguous language in {{stk:STK-NEEDS-002}}. The phrase “sufficient spatial resolution” fails the testability test. Replaced with “ground sample distance of 3 cm per pixel or finer.”

Verification coverage: 13/32 SUB+IFC requirements. All 13 IFC requirements had VER entries but none of the 19 SUB requirements did. Five safety-critical SUB requirements lacked any verification method.

Diagrams unpopulated. All 7 diagrams (context, decomposition, 2x Navigation internal, 2x Imaging internal, plus a test diagram) have 0 blocks and 0 connectors in the render output despite the baseline showing 66 blocks and 41 connectors — suggesting blocks were created at the API level but the render command shows empty output. Two duplicate internal diagrams exist for both decomposed subsystems.

Lint: 2 low findings unchanged. The 71% Jaccard between {{entity:Precision Agriculture Drone Fleet}} {{hex:D5F77259}} and the phrase fragment “flight controller and distributing hardware trigger pulses” {{hex:54F57238}} is an ontological artefact from lint classifying a sentence fragment, not a real component ambiguity. 1 previously acknowledged lint finding unchanged.

Corrections

Rationale added to all 76 requirements. Each rationale is specific to its requirement:

• STK rationales reference regulatory drivers (EPA FIFRA, FAA Part 107) and economic thresholds
• SYS rationales explain derivation of performance values from stakeholder needs — e.g., {{sys:SYS-REQS-001}} 25 ha/hr derived from {{stk:STK-NEEDS-001}} 200 ha / 8 hr
• SUB rationales connect component parameters to system-level constraints — e.g., {{sub:SUB-REQS-008}} ±0.3 m AGL traces to {{sys:SYS-REQS-004}} ±5% application rate
• IFC rationales justify protocol choices, data rates, and bus selections against engineering constraints
• VER rationales explain why each test method provides adequate evidence

{{stk:STK-NEEDS-002}} rewritten from ambiguous “sufficient spatial resolution” to quantified “3 cm GSD per pixel or finer.”

5 new VER entries created for critical SUB requirements:

• {{sub:SUB-REQS-001}} → {{sub:VER-METHODS-014}}: EKF navigation accuracy flight test with RTK denial
• {{sub:SUB-REQS-002}} → {{sub:VER-METHODS-015}}: Attitude tracking in 15 kt wind
• {{sub:SUB-REQS-005}} → {{sub:VER-METHODS-016}}: Multi-vehicle fleet separation test
• {{sub:SUB-REQS-009}} → {{sub:VER-METHODS-017}}: Sensor fault injection during flight
• {{sub:SUB-REQS-015}} → {{sub:VER-METHODS-018}}: 30-minute sustained storage write test

All 5 new VER entries traced to their parent SUB requirements. VER coverage now 18/32 (56%) SUB+IFC requirements.

flowchart TB
    SYS[Precision Agriculture Drone Fleet]
    NAV[Navigation and Flight Control]
    IMG[Imaging and Remote Sensing]
    SPR[Spray Application]
    PWR[Power and Battery Management]
    COM[Communication and Datalink]
    DAT[Data Processing and Analytics]
    AIR[Airframe and Propulsion]
    GCS[Ground Control Station]

    SYS --> NAV
    SYS --> IMG
    SYS --> SPR
    SYS --> PWR
    SYS --> COM
    SYS --> DAT
    SYS --> AIR
    SYS --> GCS

    FC[Flight Controller]
    GNSS[GNSS Receiver RTK]
    IMU[MEMS IMU]
    BARO[Barometric Sensor]
    RADAR[Radar Altimeter]
    MAG[Magnetometer]
    OBS[Obstacle Sensor]

    NAV --> FC
    NAV --> GNSS
    NAV --> IMU
    NAV --> BARO
    NAV --> RADAR
    NAV --> MAG
    NAV --> OBS

    MSC[Multispectral Camera]
    TIR[Thermal IR Camera]
    RGB[RGB Camera]
    TRIG[Trigger Controller]
    GIMB[Camera Gimbal]
    DLS[Downwelling Light Sensor]
    SSD[Image Storage NVMe]

    IMG --> MSC
    IMG --> TIR
    IMG --> RGB
    IMG --> TRIG
    IMG --> GIMB
    IMG --> DLS
    IMG --> SSD

Residual

14/19 SUB requirements still lack VER entries. The 5 created this session cover the highest-criticality items. Remaining SUB verification entries should be added during the next QC or decomposition session, prioritising SUB-REQS-003 (geofence), SUB-REQS-004 (failsafe), and SUB-REQS-006 (obstacle avoidance).

Duplicate diagrams. Two internal diagrams exist for both Navigation and Imaging subsystems. The duplicates should be deleted in a future session after confirming which ID is canonical.

6 undecomposed subsystems. Spray Application, Power and Battery Management, Communication and Datalink, Data Processing and Analytics, Airframe and Propulsion, and Ground Control Station remain at subsystem level with no component decomposition, no SUB requirements, and no IFC requirements. The next decomposition session should prioritise Spray Application (highest interface density with Navigation subsystem) and Power and Battery Management (safety-critical battery swap requirements).

Next

Resume decomposition (Flow B). Priority: decompose {{entity:Spray Application Subsystem}} into components — nozzle array, flow controller, tank and plumbing, pump, and spray boom geometry. This subsystem has the tightest coupling to Navigation (via {{ifc:IFC-DEFS-005}} CAN bus) and the most directly safety-relevant chemical application requirements. Second priority: {{entity:Power and Battery Management Subsystem}} given the 90-second swap requirement and fleet availability dependency.