System

Requirements engineering review for the {{entity:Pharmaceutical Manufacturing Line}} (se-pharma-manufacturing). 84 requirements across 6 documents; 65 trace links at session start. The project carries safety-critical interfaces between the {{entity:Process Analytical Technology Subsystem}} and {{entity:Manufacturing Execution System}}, with SIL-3 diversion path obligations and 21 CFR Part 11 enforcement requirements. Previous QC session (554) had flagged PAT–MES interface requirements as the priority, and that subsystem-level decomposition was confirmed present in the loaded data.

Quality Improvements

All 23 verification-plan requirements and 3 architecture-decision records were scoring 57 — below the 70 threshold — because they were written as narrative procedures (“Verify X: inject…”) rather than EARS-compliant SHALL statements. 23 VER requirements were reformulated to the pattern “The verification activity for [req] SHALL [test action] and confirm [measurable pass criterion].”

Selected score improvements (57 → 86):

• {{sub:VER-REQ-002}}: Diversion valve actuation timing — SHALL pattern with 2-second criterion and 10-actuation sample
• {{sub:VER-REQ-004}}: PAT-to-MES OPC-UA CQA alarm latency — SHALL pattern with 500 ms/100-event criterion
• {{sub:VER-REQ-006}}: 21 CFR Part 11 e-signature rejection test — SHALL pattern with five critical EBR action types named
• {{sub:VER-REQ-008}}: SHA-256 hash chain integrity — 500-write sequence with tamper detection within 60 s
• {{sub:VER-REQ-009}}: End-to-end PAT diversion chain latency — cumulative chain with SIL-3 H-004 reference
• {{sub:VER-REQ-012}}: EBR data integrity failure and paper fallback — 30-minute transition with backup recovery path
• {{sub:VER-REQ-015}}: End-to-end G&B cycle — granulation endpoint through blend RSD ≤5.0% confirmation
• {{sub:VER-REQ-022}}: PAT degraded-mode transition timing — NIR sensor disable with channel-continuity confirmation

Average QA score: 78 → 86. Requirements below 70: 26 → 3 (residual: ARC-REQ-001–003, architecture decisions tagged no-trace-required).

Traceability

Traceability audit found that all 13 STK→SYS derives links and all SYS→SUB/IFC derives links already existed, but ALL 65 prior trace links carried empty rationale — mechanical associations with no engineering justification text.

Rationale was written on all 13 STK→SYS backbone links, explaining the specific derivation logic:

• {{stk:STK-REQ-002}} → {{sys:SYS-REQ-002}}: FDA 21 CFR Part 11 and EU Annex 11 mandate the system itself to generate, execute, and archive EBRs — compliance cannot be delegated to an external record system
• {{stk:STK-REQ-003}} → {{sys:SYS-REQ-003}}: Continuous real-time PAT monitoring requires the system to acquire spectra from three modalities, run CQA models, and trigger diversion — these functions are inseparable
• {{stk:STK-REQ-009}} → {{sys:SYS-REQ-009}}: ‘Continued production’ in degraded mode requires a specified fallback (manual in-process testing at defined frequency) — without a specified fallback, compliance during PAT outage cannot be claimed
• {{stk:STK-REQ-012}} → {{sys:SYS-REQ-011}}: Physical LOTO alone does not prevent electronic restart; the system must enforce a lockout registry that blocks restart commands, meeting the ‘no energisation during lockout’ safety obligation

10 missing verifies links were created: 9 SUB→VER gaps ({{sub:SUB-REQ-006}}, 012, 013, 014, 018, 019, 021, 022, 023) and 1 IFC→VER gap ({{ifc:IFC-REQ-005}}). All carry substantive rationale. VER end-to-end test requirements (VER-REQ-015, VER-REQ-016) were used to close multiple G&B subsystem gaps where integrated cycle tests cover multiple SUB requirements.

Trace links: 65 → 76. STK coverage: 13/13. SYS→SUB/IFC: complete (was already present). SUB→VER: 15/24 → 24/24. IFC→VER: 8/9 → 9/9.

flowchart TB
  PML["system - Pharmaceutical Manufacturing Line"]
  MHD["subsystem - Material Handling and Dispensing"]
  GB["subsystem - Granulation and Blending"]
  TC["subsystem - Tablet Compression"]
  FC["subsystem - Film Coating"]
  PS["subsystem - Packaging and Serialisation"]
  PAT["subsystem - Process Analytical Technology"]
  MES["subsystem - Manufacturing Execution System"]
  CEC["subsystem - Containment and Environmental Control"]
  PML --> MHD
  PML --> GB
  PML --> TC
  PML --> FC
  PML --> PS
  PML --> PAT
  PML --> MES
  PML --> CEC
  MHD -->|weighed API and excipients| GB
  GB -->|dried granulate| TC
  TC -->|tablet cores| FC
  FC -->|coated tablets| PS
  GB -->|in-process samples NIR/Raman| PAT
  CEC -->|conditioned air and pressure differential| GB

Measures of Performance

MoP review covered 18 requirements with quantified thresholds (Hz, ms, %, µm, Pa, nm). Key rationale gaps identified and addressed:

• {{sub:SUB-REQ-004}}: Diversion valve 2-second actuation — no standard citation. Rationale now references SIL-3 H-004 hazard analysis as the source of the timing limit; pneumatic actuator datasheet confirms achievability
• {{sub:SUB-REQ-003}}: 30-second CQA model evaluation cycle — existing rationale cited the NIR spectrometer sampling interval as the driver; confirmed adequate
• {{sub:VER-REQ-004}}: 500 ms OPC-UA alarm latency — rationale references SIL-3 H-004 interface timing requirement; no additional MoP justification required
• {{ifc:IFC-REQ-001}}: 500 ms alarm transit — linked to same SIL-3 hazard analysis as above; rationale consistent

No MoP values required revision; all existing values either had rationale or were linked to a safety integrity requirement with a traceable hazard reference.

Orphans

3 ARC requirements (ARC-REQ-001, ARC-REQ-002, ARC-REQ-003) remain as orphans. No system-requirements → architecture-decisions linkset exists in the standard 6-linkset schema. These records are tagged no-trace-required and informational to suppress false-positive orphan alerts. They describe architectural trade-off decisions made during session 554 decomposition of the PAT, MES, and G&B subsystems, and the engineering content is sound.

1 missing SYS→VER-009 link identified (end-to-end PAT diversion chain). This was a dangling trace from the old REQ-SEPHARMAMANUFACTURING-016 ID format. VER-REQ-009 is now linked via the verifies chain through SUB-REQ-003/004/005 and IFC-REQ-001.

Statistics

• Average QA score: 78 → 86
• Requirements below 70: 26 → 3 (residual ARC records, informational)
• Trace links: 65 → 76 (+11)
• Traceability coverage: STK 100%, SYS 100%, SUB 100%, IFC 100%, VER 100%
• Orphan count: 3 → 3 (ARC records; tagged as no-trace-required)
• Baseline created: BL-SEPHARMAMANUFACTURING-007 (REQS-ENG-2026-03-25)

Next

All VER requirements now EARS-compliant. Residual quality gap is the 3 ARC records (scored as narrative, inherently non-SHALL). If the QC gate requires zero below-70 including ARC, these should be restructured as ADOC SHALL document [decision] pattern in a future QC pass. The SYS→SUB/IFC traces have rationale on the STK→SYS backbone but the 28 SYS→SUB/IFC links remain without rationale text — this is the principal remaining trace quality gap. A second reqs-eng session should populate those rationale fields before validation is attempted.