Requirement Traceability Matrix (RTM)

Safety-critical certification standards—such as DO-178C (Aerospace), ISO 26262 (Automotive), ECSS (Space), and IEC 62304 (Medical)—mandate bidirectional traceability between system requirements, architecture design, formal verification outcomes, and generated code artifacts.

fsmc automates this verification workflow via the RtmEmitter.

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1. Tagging Requirements in Models

Requirements can be attached to states, transitions, and formal properties using the @fsm:req directive:

package AerospaceEngine {
    state def EngineController {
        // Tagged State
        @fsm:req "REQ-ENG-SAFE-01"
        state SafeShutdown;

        state Running {
            // Tagged Transition
            @fsm:req "REQ-ENG-EMERG-02"
            transition on EmergencyStop to SafeShutdown;
        }

        // Tagged Formal LTL Property
        @fsm:req "REQ-ENG-SAFE-01"
        @fsm:property SafeShutdownGuaranteed = "G (EmergencyStop -> F SafeShutdown)";
    }
}

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2. Generating Compliance Reports

To generate the traceability report during compilation:

Markdown Audit ReportJSON Structured Schema

fsmc -i engine.sysml --rtm-output engine_rtm.md

fsmc -i engine.sysml --rtm-output engine_rtm.json

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3. Sample Report Format

Generated Markdown Report

# Requirement Traceability Matrix (RTM): EngineController

**Verification Compliance:** 100.0% (2/2 Requirements Verified)

| Requirement ID | Description | Covered States | Covered Transitions | Formal Properties | Status |
| :--- | :--- | :--- | :--- | :--- | :--- |
| `REQ-ENG-EMERG-02` | Emergency stop response | - | `Running -> SafeShutdown` | - | **PASSED** |
| `REQ-ENG-SAFE-01` | Safe shutdown guarantee | `SafeShutdown` | - | `SafeShutdownGuaranteed` | **PASSED** |

Generated JSON Schema (for CI/CD Integration)

{
  "fsm_name": "EngineController",
  "total_requirements": 2,
  "verified_requirements": 2,
  "compliance_percentage": 100.0,
  "requirements": [
    {
      "id": "REQ-ENG-SAFE-01",
      "description": "Safe shutdown guarantee",
      "covered_states": ["SafeShutdown"],
      "covered_transitions": [],
      "formal_properties": ["SafeShutdownGuaranteed"],
      "status": "PASSED"
    }
  ]
}