{
  "schema": "semiagora.process-simulation.v1",
  "experiment_id": "SA-PROC-METRO-SPC-CAPABILITY-001",
  "title": "SPC and process-capability replay",
  "execution_mode": "precomputed-only",
  "model_boundary": "Educational SPC and capability replay. It teaches control-chart and Cp/Cpk vocabulary; it is not a production statistical-process-control system or release decision.",
  "lesson_route": "/learn/process-metrology",
  "simulation_route": "/simulations/process-spc-capability",
  "measurement_context": {
    "metric": "critical_dimension_nm",
    "target_nm": 100,
    "lower_spec_limit_nm": 96,
    "upper_spec_limit_nm": 104,
    "sample_count": 25
  },
  "samples_nm": [
    100.2, 99.1, 101.3, 100.6, 98.9,
    100.8, 101.1, 99.7, 100.4, 102.0,
    98.7, 99.8, 100.1, 101.5, 100.9,
    99.5, 100.7, 101.8, 98.8, 100.0,
    99.3, 100.5, 101.0, 100.6, 99.9
  ],
  "derived_metrics": {
    "mean_nm": 100.29,
    "sample_std_nm": 0.92,
    "cp": 1.44,
    "cpk": 1.34,
    "out_of_spec_points": 0,
    "high_side_margin_nm": 3.71,
    "low_side_margin_nm": 4.29
  },
  "methods": [
    "Compute sample mean and sample standard deviation from the saved CD list.",
    "Compute Cp as specification width divided by six sample standard deviations.",
    "Compute Cpk as the smaller of the high-side and low-side distance to specification divided by three sample standard deviations.",
    "Report out-of-spec count separately from capability so excursions and spread are not confused."
  ],
  "limitations": [
    "No subgrouping, Western Electric rules, gauge R&R, autocorrelation, non-normality, drift correction, or production SPC alarm handling is included.",
    "No qualified metrology, manufacturing release, facility dashboard, wafer acceptance, or process-control claim is implied.",
    "Real SPC evidence requires sampling plan, measurement-system analysis, time order, control limits, operator/tool context, and rights-clean data.",
    "This replay is not a process recipe, release gate, or statistical guarantee."
  ],
  "sources": [
    {
      "label": "NIST/SEMATECH Engineering Statistics Handbook chapter 6",
      "url": "https://www.nist.gov/publications/nistsematech-engineering-statistics-handbook-chapter-6-process-or-product-monitoring",
      "note": "Public NIST/SEMATECH process/product monitoring handbook chapter."
    },
    {
      "label": "NIST process capability",
      "url": "https://www.itl.nist.gov/div898/handbook/pmc/section1/pmc16.htm",
      "note": "Public NIST handbook page defining process capability indices including Cp and Cpk."
    }
  ]
}