# Inject Faults

Add, configure, and manage faults on Simulink, Simscape, and System Composer model...

- Repository: https://github.com/matlab/simulink-agentic-toolkit (1305 stars)
- Category: Testing
- License: see repository
- Last updated: 2026-10-29
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add matlab/simulink-agentic-toolkit --skill inject-faults -g -a claude-code -y`
Codex: `npx skills add matlab/simulink-agentic-toolkit --skill inject-faults -g -a codex -y`
Cursor: `npx skills add matlab/simulink-agentic-toolkit --skill inject-faults -g -a cursor -y`
Gemini CLI: `npx skills add matlab/simulink-agentic-toolkit --skill inject-faults -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add matlab/simulink-agentic-toolkit`

## Description

Add, configure, and manage faults on Simulink, Simscape, and System Composer model signals for robustness analysis and safety validation. Use when injecting faults (stuck, noise, gain, offset) onto block inports/outports, enabling fault simulation, or analyzing fault effects. Covers sensor failures, signal corruptions, actuator faults, FMEA validation, and robustness testing. Requires Simulink Fault Analyzer.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Fault Injection

Use `evaluate_matlab_code` with the `Simulink.fault` API to programmatically inject faults into Simulink models. Faults override signal values at block ports to simulate hardware failures, sensor faults, and actuator malfunctions.

## When to Use

- Injecting sensor stuck-at faults, noise, or bias for safety analysis (Simulink, Simscape, System Composer)
- Validating FMEA failure modes through simulation
- Testing controller robustness against actuator or sensor failures
- Adding fault placeholders (without behavior) for FMEA traceability before defining fault logic
- Configuring fault trigger conditions (timed, conditional, always-on)
- Creating fault scenarios for automated testing
- Comparing nominal vs. faulted behavior
- Linking faults to FMEA failure mode cells
- Generating fault specification reports
- Exporting models with embedded fault behavior for teams without Simulink Fault Analyzer
- Registering custom fault behavior libraries
- Synchronizing (also called **resync** / **sync** / **synchronize faults** / **update fault references**) fault information from referenced models, subsystems, or linked libraries into a parent model

## When NOT to Use

- Creating FMEA spreadsheets or safety analysis documents -> use `manage-safety-analysis`
- Building or editing model structure -> use `building-simulink-models`
- Running standard (non-faulted) simulations -> use `simulating-simulink-models`
- Writing pass/fail tests -> use `testing-simulink-models`

## Probe

```matlab
hasFA = ~isempty(which('Simulink.fault.addFault'));
fprintf('Simulink Fault Analyzer available: %d\n', hasFA);
```

## Key Concepts

The rest: https://github.com/matlab/simulink-agentic-toolkit/blob/HEAD/skills-catalog/verification-validation-and-test/inject-faults/SKILL.md