Requirement traceability is the ability to link system requirements to design elements, implementation, and test cases throughout the development lifecycle.
Traceability ensures:
- Every requirement is implemented
- Every implementation has a requirement
- Verification coverage is complete
Links: Requirement → Model → Code → Test Case
Automotive Example:
Brake pressure control requirement linked to ABS control subsystem.
Traceability is required by safety standards and lifecycle processes.
It ensures requirements are implemented, verified, and validated.
Automotive Example:
Traceability between safety requirements and ESC controller logic.
Bidirectional traceability includes:
- Forward: Requirement → Implementation
- Backward: Implementation → Requirement
Automotive Example:
Cruise control requirement linked both ways to model blocks.
Tools provide requirement linking, traceability matrices, and verification reports.
Automotive Example:
Linking ADAS perception requirements to subsystem logic.
A matrix mapping requirements to design and test cases.
Automotive Example:
ABS requirements mapped to test cases.
Associates model elements with requirements using metadata.
Automotive Example:
Brake slip block linked to requirement.
Ensures implementation meets requirements via simulation and testing.
Automotive Example:
ABS model simulation for slip control.
Ensures system meets intended use and user expectations.
Automotive Example:
Real vehicle braking tests.
Breaking large requirements into smaller subsystems.
Automotive Example:
Braking → ABS + actuator requirements.
Assigning requirements to system components.
Automotive Example:
Torque control assigned to ECU.
Ensures all requirements have implementation and tests.
Automotive Example:
Missing braking fault test case detected.
Organizing requirements into system, subsystem, and software levels.
Automotive Example:
Vehicle stability → ESC software.
Test cases are mapped to requirements for verification.
Automotive Example:
Testing cruise control tolerance.
A missing link between requirement and implementation/test.
Automotive Example:
Unlinked emergency braking requirement.
Report showing links between requirements, models, and tests.
Automotive Example:
Safety audit report.
Managing updates to requirements and ensuring consistency.
Automotive Example:
Updating braking algorithm.
Using tags to identify requirement links in model elements.
Automotive Example:
Tagging safety logic blocks.
Using existing requirements across projects or variants.
Automotive Example:
Shared braking requirements.
Linking generated code back to models and requirements.
Automotive Example:
ECU code mapped to safety requirement.
Ensures tests validate specific requirements.
Automotive Example:
Braking response time test.
Model-in-the-loop verifies model behavior vs requirements.
Automotive Example:
ABS slip control simulation.
Software-in-the-loop verifies generated code.
Automotive Example:
Cruise control logic testing.
Hardware-in-the-loop validates ECU behavior on hardware.
Automotive Example:
Emergency braking ECU testing.
Review of traceability for compliance.
Automotive Example:
Braking ECU safety audit.
Maintaining traceability across all development phases.
Automotive Example:
Requirement to vehicle testing trace.
A fixed set of approved requirements.
Automotive Example:
Braking system release baseline.
Identifying contradictory requirements.
Automotive Example:
Conflicting cruise speed limits.
Linking safety goals to implementation.
Automotive Example:
ESC safety goal to algorithm.
Automated tools maintain requirement links.
Automotive Example:
Auto-generated traceability matrix.
- Bidirectional linking
- Use automation tools
- Maintain hierarchy
- Regular reviews
Automotive Example:
Traceability for braking ECU certification.