# Safety Review of ENG-2 Deliverables

**Document ID:** REV-ENG2-001  
**Version:** 1.0  
**Date:** 2026-03-06  
**Reviewer:** Safety Officer  
**Status:** REVIEW COMPLETE - DELIVERABLES MISSING  
**Classification:** SAFETY-CRITICAL

---

## 1. Executive Summary

This document provides the Safety Officer's review of ENG-2's (ROS Safety Lead) deliverables for the v0.6.1 Foundation Phase.

**Review Status:** ⚠️ **DELIVERABLES NOT FOUND**

The following expected deliverables from ENG-2 were not located in the project documentation:
- `docs/SAFETY_ARCHITECTURE_V1.md` - **MISSING**
- `docs/SAFETY_TEST_PLAN.md` - **MISSING**

---

## 2. Review Checklist Status

The following checklist items could not be evaluated due to missing documentation:

| Checklist Item | Status | Notes |
|----------------|--------|-------|
| Hardware/software separation adequate? | ⚠️ NOT REVIEWED | Document not found |
| Timing requirements (<10ms validation, <50ms e-stop) achievable? | ⚠️ NOT REVIEWED | Document not found |
| 3-layer defense sufficient? | ⚠️ NOT REVIEWED | Document not found |
| Watchdog design (1kHz) appropriate? | ⚠️ NOT REVIEWED | Document not found |
| Safety certificate 30s validity window adequate? | ⚠️ NOT REVIEWED | Document not found |
| Emergency stop authorization requirements correct? | ⚠️ NOT REVIEWED | Document not found |
| Integration points with AI layer safe? | ⚠️ NOT REVIEWED | Document not found |
| Test scenarios comprehensive? | ⚠️ NOT REVIEWED | Document not found |

---

## 3. Findings

### 3.1 Missing Deliverables

**CRITICAL ISSUE:** ENG-2 has not produced the required safety architecture and test plan documents as specified in the v0.6.1 Sprint Plan.

**Expected per V061_SPRINT_PLAN.md:**
- Week 1: "Create safety requirement specification (SRS)" - **COMPLETED** (by Safety Officer)
- Week 1: "Write SRS document" - **COMPLETED** (by Safety Officer)
- Week 1: "Create safety test plan" - **MISSING**
- Week 4: "Complete safety layer (4 nodes)" - **STATUS UNKNOWN**

### 3.2 Impact Assessment

| Impact Area | Severity | Description |
|-------------|----------|-------------|
| **Gate 1 Readiness** | CRITICAL | Cannot pass Gate 1 without safety architecture documentation |
| **Implementation Risk** | HIGH | ROS Safety Lead deliverables are on the critical path |
| **Safety Validation** | CRITICAL | No documented test plan for 50+ safety scenarios |
| **Team Coordination** | MEDIUM | Other engineers depend on safety interfaces |

---

## 4. Recommendations

### 4.1 Immediate Actions Required

1. **ENG-2 Status Check** - Project Manager to confirm ENG-2 assignment and availability
2. **Deliverable Recovery** - Determine if documents exist in another location/format
3. **Backup Planning** - Assign backup resources if ENG-2 unavailable

### 4.2 Document Requirements

If/when ENG-2 produces the deliverables, they MUST include:

#### For SAFETY_ARCHITECTURE_V1.md:
- [ ] System architecture diagram showing safety layer components
- [ ] Hardware/software separation boundaries
- [ ] Data flow diagrams for safety-critical paths
- [ ] Component interaction specifications
- [ ] Failure mode analysis for each component
- [ ] Timing analysis for all safety-critical operations
- [ ] Interface definitions for `/safety/validator`, `/safety/limits`, `/safety/emergency_stop`, `/safety/watchdog`

#### For SAFETY_TEST_PLAN.md:
- [ ] Test strategy and methodology
- [ ] Test environment requirements
- [ ] Test case mapping to SRS requirements
- [ ] Pass/fail criteria for each test
- [ ] Test automation approach
- [ ] Coverage metrics and targets

### 4.3 Timing Considerations

Per the Sprint Plan:
- **Week 4** requires "Safety scenario tests (50 scenarios)"
- **Gate 1** requires "Zero safety violations in simulation"
- **Current Status:** At risk of missing Week 4 deliverables

---

## 5. Approval Status

### Overall Status: **CHANGES REQUIRED - DELIVERABLES MISSING**

The review cannot be completed because ENG-2's deliverables are not available for review.

### Required for Approval:
1. ✅ SAFETY_REQUIREMENTS_SPEC.md (completed by Safety Officer)
2. ❌ SAFETY_ARCHITECTURE_V1.md (missing - ENG-2)
3. ❌ SAFETY_TEST_PLAN.md (missing - ENG-2)
4. ❌ Safety layer implementation (4 nodes) - status unknown

---

## 6. Safety Officer Concerns

### 6.1 Process Concerns

| Concern | Priority | Description |
|---------|----------|-------------|
| Missing safety lead deliverables | CRITICAL | Core safety documentation not produced |
| Gate 1 at risk | CRITICAL | Week 4 deadline approaching without architecture |
| Interface freeze impact | HIGH | Other teams may be blocked waiting for safety interfaces |

### 6.2 Technical Concerns (Based on Sprint Plan Only)

Based solely on the Sprint Plan (V061_SPRINT_PLAN.md), the following areas require careful review when documentation becomes available:

1. **Timing Requirements:** The plan specifies <10ms validation and <50ms e-stop. These are aggressive targets that require rigorous proof.

2. **Watchdog Design:** 1kHz monitoring with 3ms e-stop trigger is demanding and needs detailed timing analysis.

3. **Safety Certificate Validity:** 30-second validity window with 5-second grace period needs justification.

4. **Hardware/Software Separation:** The plan mentions "simulation placeholder" for hardware limits - this needs concrete hardware integration plan.

---

## 7. Sign-Off

| Role | Name | Signature | Date | Status |
|------|------|-----------|------|--------|
| Safety Officer | (Subagent) | Digital | 2026-03-06 | REVIEW INCOMPLETE |

**Authority Statement:**
As Safety Officer, I cannot approve the safety architecture for v0.6.1 without reviewing ENG-2's deliverables. This review is blocked pending receipt of:
- `docs/SAFETY_ARCHITECTURE_V1.md`
- `docs/SAFETY_TEST_PLAN.md`

**Next Steps:**
1. Project Manager to follow up with ENG-2
2. Reschedule review within 48 hours of document receipt
3. If documents not received by Week 3, escalate to project leadership

---

## 8. Appendices

### Appendix A: Requirements from Sprint Plan

From V061_SPRINT_PLAN.md, ENG-2's Week 1 deliverables should include:

```
#### ENG-2 (ROS Safety): Safety Architecture Design
- [ ] Define safety-critical ROS services:
  - `/safety/validate_motion` (input: trajectory, output: approval+certificate)
  - `/safety/get_limits` (output: current safety limits)
  - `/safety/emergency_stop` (input: trigger, output: confirmation)
- [ ] Define safety message types:
  - `SafetyCertificate.msg` (validation_id, expiry, constraints_checked)
  - `EmergencyStop.msg` (triggered, source, timestamp)
  - `SafetyLimits.msg` (max_velocity, max_force, workspace_bounds)
- [ ] Document timing requirements: <10ms validation response
- [ ] Create safety requirement specification (SRS)

**Deliverable:** Safety interface specification, hardware requirements list
```

### Appendix B: Week 4 Deliverables

```
#### ENG-2 (ROS Safety): Emergency Stop & Watchdog
- [ ] Implement `/safety/emergency_stop` node
  - Physical relay control (simulation placeholder)
  - <50ms response time
  - Cannot be overridden
- [ ] Implement `/safety/watchdog` node
  - 1kHz heartbeat monitoring
  - Auto-trigger e-stop on failure
- [ ] Safety scenario tests (50 scenarios)
  - Human appearance
  - Sensor failure
  - Unsafe commands
  - Network latency

**Deliverable:** Complete safety layer (4 nodes)
```

---

**END OF DOCUMENT**

*This document is classified SAFETY-CRITICAL. Changes require Safety Officer approval.*
