stress testing
**Stress Testing** for ML models is the **systematic evaluation of model performance under extreme or challenging conditions** — pushing inputs beyond typical operating ranges to identify failure modes, performance degradation, and the limits of reliable model operation.
**Stress Testing Approaches**
- **Distribution Shift**: Test on data from different distributions (different fab, different product, different time period).
- **Extreme Values**: Feed inputs at the boundaries or beyond the training data range.
- **Noise Injection**: Add increasing levels of noise to inputs to find the noise threshold for failure.
- **Adversarial**: Apply adversarial perturbations of increasing strength.
**Why It Matters**
- **Failure Discovery**: Stress testing reveals failure modes invisible in standard accuracy evaluation.
- **Operating Envelope**: Defines the reliable operating envelope of the model — where it can and cannot be trusted.
- **Production Safety**: Models deployed in semiconductor fabs must be tested under stress before controlling real processes.
**Stress Testing** is **pushing the model to its limits** — finding where and how the model breaks to ensure safe deployment.