machine capability

**Machine capability** is the **assessment of intrinsic equipment repeatability under tightly controlled input conditions** - it isolates tool precision from broader process variation and is central to equipment qualification. **What Is Machine capability?** - **Definition**: Capability study focused on machine repeatability, commonly expressed as Cm or Cmk. - **Test Setup**: Repeated runs on uniform material with controlled environment and minimal operator variation. - **Measured Scope**: Primarily short-term repeatability and centering of the equipment itself. - **Acceptance Use**: Factory acceptance and site acceptance decisions often rely on machine capability thresholds. **Why Machine capability Matters** - **Tool Qualification**: Ensures equipment quality before blaming broader process factors. - **Root-Cause Isolation**: Separates machine precision issues from material or recipe variability. - **Maintenance Strategy**: Capability decline can trigger preventive calibration or hardware service. - **Line Matching**: Supports tool-to-tool alignment for predictable multi-tool production. - **Risk Reduction**: Prevents unstable equipment from entering high-volume flow. **How It Is Used in Practice** - **Protocol Definition**: Use standardized sample, run count, and environmental conditions for comparability. - **Metric Calculation**: Compute Cm and Cmk with confidence bounds and centering diagnostics. - **Corrective Action**: Recalibrate, repair, or retune tools that miss acceptance criteria. Machine capability is **the precision health check of manufacturing equipment** - strong tool repeatability is the foundation on which process capability is built.