Documentation: Multi-Standard Safety Architecture User Guide

[avrabe]

Overview

Create comprehensive documentation for the new four-layer safety architecture, including user guides, migration documentation, and qualification evidence templates.

Parent Issue: #101
Depends on: #102, #103, #104

Documentation Scope

1. Architecture Documentation

System Architecture Guide

• Four-Layer Architecture Overview: Detailed explanation of memory management, safety capabilities, safety standards, and safety levels
• Layer Interaction Diagrams: Visual representation of how layers compose
• Feature Dependency Maps: Clear documentation of feature relationships and constraints
• Qualification Constraints: Detailed explanation of why std cannot be used in safety-critical contexts

Multi-Standard Support Guide

• Standards Comparison Matrix: Side-by-side comparison of all 6 supported standards
• Severity Score Mapping: Documentation of universal 0-1000 severity scoring system
• Cross-Standard Compatibility: How different standards can interoperate
• Domain-Specific Guidance: When to use each standard (automotive, aerospace, medical, etc.)

2. User Documentation

Quick Start Guide

# Quick Start: Safety-Critical WebAssembly Runtime

## Automotive (ISO 26262)
```toml
# For ASIL-D automotive applications
[dependencies]
wrt = { version = \"*\", features = [\"iso-26262\", \"asil-d\"] }

Aerospace (DO-178C)

# For DAL-A aerospace applications
[dependencies]
wrt = { version = \"*\", features = [\"do-178c\", \"dal-a\"] }

Medical (IEC 62304)

# For Class C medical devices
[dependencies]
wrt = { version = \"*\", features = [\"iec-62304\", \"class-c\"] }

#### Feature Selection Guide
- [ ] **Safety Level Selection**: How to choose appropriate safety levels for your application
- [ ] **Memory Strategy Selection**: When static/bounded/managed allocation is appropriate
- [ ] **Capability Composition**: How to combine safety capabilities for specific requirements
- [ ] **Common Combinations**: Pre-defined feature combinations for typical use cases

#### Migration Guide
- [ ] **From Legacy Features**: Step-by-step migration from old mixed features
- [ ] **Breaking Changes**: Comprehensive list of breaking changes and solutions
- [ ] **Compatibility Matrix**: What works with what across versions
- [ ] **Code Examples**: Before/after code examples for common patterns

### 3. API Documentation

#### Safety-Qualified APIs
- [ ] **Type System Documentation**: How safety-qualified types work
- [ ] **Memory Management APIs**: Documentation of safety-aware allocation
- [ ] **Safety Context Usage**: How to use safety contexts in applications
- [ ] **Verification APIs**: How to implement and use safety verification

#### Code Examples
```rust
// Example: ASIL-D automotive application
#[cfg(all(feature = \"iso-26262\", feature = \"asil-d\"))]
fn automotive_critical_function() -> Result<()> {
    // Use static allocation for highest safety level
    let provider = safety_alloc\!(1024, CrateId::Component)?;
    let mut data = BoundedVec::new(provider)?;
    
    // Formal verification required at ASIL-D
    safety_guarded\!(SAFETY_CONTEXT, \"critical_operation\", {
        // Safety-critical processing
        process_automotive_data(&mut data)?;
        Ok(())
    })
}

// Example: DO-178C aerospace application  
#[cfg(all(feature = \"do-178c\", feature = \"dal-a\"))]
fn aerospace_critical_function() -> Result<()> {
    let ctx = universal_safety_context\!(Do178c(DalA));
    
    // Coverage analysis required for DAL-A
    let guard = SafetyGuard::new(&ctx, \"flight_control_operation\")?;
    
    // Process flight-critical data
    let result = process_flight_data()?;
    
    guard.complete()?;
    Ok(result)
}

4. Qualification Documentation

Certification Templates

• ISO 26262 Artifacts: Templates for automotive functional safety documentation
• DO-178C Artifacts: Templates for aerospace software certification
• IEC 61508 Artifacts: Templates for industrial functional safety
• IEC 62304 Artifacts: Templates for medical device software lifecycle
• EN 50128 Artifacts: Templates for railway safety-critical software
• ISO 25119 Artifacts: Templates for agricultural machinery safety

Requirements Traceability

• Safety Requirements Matrix: Mapping WRT features to safety requirements
• Test Coverage Matrix: Mapping tests to safety requirements
• Verification Evidence: Documentation of formal verification results
• Qualification Checklists: Step-by-step qualification validation

Evidence Generation

# Generate qualification documentation
cargo wrt requirements matrix --standard iso-26262 --level asil-d --output docs/

# Generate formal verification evidence
cargo wrt kani-verify --features=\"iso-26262,asil-d\" --evidence-output docs/verification/

# Generate coverage reports
cargo wrt test-features --coverage mcdc --output docs/coverage/

5. Development Documentation

Contributor Guide

• Architecture Principles: How to maintain the four-layer separation
• Feature Development: How to add new safety capabilities
• Testing Requirements: What tests are required for safety-critical code
• Code Review Guidelines: Safety-specific code review checklist

Maintenance Documentation

• Feature Lifecycle: How features are added, deprecated, and removed
• Backward Compatibility: How to maintain compatibility across versions
• Safety Validation: How to validate safety properties during development
• Release Process: Special requirements for safety-critical releases

Implementation Tasks

Documentation Infrastructure:

• Set up documentation build system with mdBook or similar
• Create documentation templates for each standard
• Implement automatic API documentation generation
• Set up documentation validation and testing

Content Creation:

• Write comprehensive architecture guide
• Create user-friendly quick start guides
• Document all feature combinations with examples
• Create migration guides with practical examples
• Write qualification documentation templates

Visual Documentation:

• Create architecture diagrams
• Design feature relationship charts
• Create decision trees for standard/level selection
• Design workflow diagrams for safety processes

Interactive Documentation:

• Create feature selection wizard
• Build qualification checklist tools
• Implement documentation search and filtering
• Add interactive code examples

Validation:

• Test all documentation examples
• Validate qualification templates with experts
• Review documentation for clarity and correctness
• Get feedback from early adopters

Deliverables

User-Facing Documentation:

• Getting Started Guide: Quick introduction to multi-standard safety
• Feature Reference: Complete reference of all features and their purposes
• Migration Guide: Step-by-step upgrade instructions
• Best Practices: Recommended patterns for each safety level

Developer Documentation:

• Architecture Guide: Deep technical documentation of the four-layer system
• API Reference: Complete API documentation with safety annotations
• Testing Guide: How to test safety-critical code effectively
• Contribution Guidelines: How to contribute safely to the project

Qualification Documentation:

• Certification Templates: Ready-to-use templates for all supported standards
• Evidence Packages: Automated generation of certification evidence
• Compliance Checklists: Validation checklists for each safety level
• Traceability Matrices: Requirements to implementation traceability

Acceptance Criteria

• Complete user guide covering all 6 safety standards
• Step-by-step migration documentation with working examples
• Qualification templates validated by safety experts
• All code examples tested and working
• Interactive documentation tools functional
• API documentation complete with safety annotations
• Multi-language support for international standards
• Documentation builds and deploys automatically
• Search and navigation work effectively
• Feedback incorporation process established

Success Metrics

• Users can successfully select appropriate safety levels without expert consultation
• Migration from legacy features can be completed following documentation alone
• Certification bodies accept generated qualification documentation
• Developer onboarding time for safety-critical development is reduced
• Support requests decrease due to comprehensive documentation
• Documentation remains current with code changes through automation