Every part comes off the line a little different. A spec says it must land between two limits; miss, and it's scrap. Scrub the process's spread and its center and watch the yield — and the capability number Cpk — move. The lesson: you need it both tight and centered.
Parts ~ N(μ, σ) against a fixed spec [8, 12] (target 10). Yield = Φ((USL−μ)/σ) − Φ((LSL−μ)/σ); Cpk = min(USL−μ, μ−LSL) / 3σ. Node-verified (centered σ=1 → 95.45%; off-center drops Cpk below Cp). Built on the reusable probe.js primitive. Runs on your device. · Institute for Physical AI @ BMI