Which testing approach involves deliberately injecting faults into the system to study robustness and failure modes?

• A. Fault-injection experiments
• B. Hardware-in-the-loop testing
• C. Monte Carlo simulations
• D. Real-world field trials

Answer: (A)

Deliberately injecting faults into a system to study its robustness and failure modes is fault-injection testing. By introducing controlled faults—such as hardware bit flips, corrupted inputs, timing anomalies, or simulated component failures—the tester observes how the system detects, handles, or recovers from problems, revealing weaknesses and ensuring safe, graceful degradation. This approach directly targets resilience, unlike hardware-in-the-loop testing which combines real hardware with a simulated environment for broader integration checks, Monte Carlo simulations that explore random outcomes without forcing specific faults, or real-world field trials that observe behavior in natural conditions without intentional faulting.