{
 "status": "AI-assisted A3 example. Case facts are synthetic example data built on the structure of Art Smalley's 2006 machine-shop grinding case; they are not production records.",
 "report_label": "AI-assisted A3 Report",
 "title": "Reduce roundness defects in shaft final grinding",
 "revision": 1,
 "scope": "Steps 1-4 composed. Steps 5-8 not yet composed.",
 "site": {
  "name": "Rockford machining site",
  "location": "Rockford, Illinois",
  "main_products": [
   "Pump shafts",
   "Valve spools",
   "Bearing sleeves"
  ],
  "focus": "PS-24 pump shaft - final grinding of bearing journals J1, J2, J3 in one setup on G-1 or G-2, measured at MS-02"
 },
 "standard": {
  "feature": "Bearing journals J1, J2, J3 - nominal Ø30 mm",
  "roundness_max_um": 3.0,
  "source": "Example drawing PS-24 rev D, note 4: roundness ≤3 µm (peak-to-valley, least-squares reference circle) on each journal",
  "overall_reject_max_pct": 0.5,
  "overall_source": "Example site quality plan QP-24: final-grind first-pass reject rate ≤0.5%"
 },
 "measurement_basis": {
  "station": "MS-02 in-line roundness gauge",
  "location": "Immediately after final grind, before wash and pack",
  "coverage": "Every shaft leaving G-1 or G-2 is measured on all three journals; 100% coverage",
  "record": "Shaft ID, machine, shift, operator, part number, week and day, roundness per journal, worst journal, primary reject code",
  "numerator": "Unique shafts rejected on first measurement",
  "denominator": "All unique first-cycle completions in the period",
  "incoming": "Blank roundness after turning and heat treat is sampled at receipt to final grind: typically 18-24 µm on both machines, same lots split between G-1 and G-2",
  "exclusions": "Rechecks and rework are excluded from numerator and denominator"
 },
 "monthly": [
  {
   "week": "Wk 1",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 2,
   "g1_roundness": 1,
   "other_rejects": 6,
   "total_rejects": 9,
   "overall_pct": 0.3,
   "g2_roundness_pct": 0.1,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 2",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 1,
   "g1_roundness": 2,
   "other_rejects": 7,
   "total_rejects": 10,
   "overall_pct": 0.3,
   "g2_roundness_pct": 0.1,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 3",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 2,
   "g1_roundness": 1,
   "other_rejects": 6,
   "total_rejects": 9,
   "overall_pct": 0.3,
   "g2_roundness_pct": 0.1,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 4",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 1,
   "g1_roundness": 2,
   "other_rejects": 7,
   "total_rejects": 10,
   "overall_pct": 0.3,
   "g2_roundness_pct": 0.1,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 5",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 2,
   "g1_roundness": 1,
   "other_rejects": 6,
   "total_rejects": 9,
   "overall_pct": 0.3,
   "g2_roundness_pct": 0.1,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 6",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 8,
   "g1_roundness": 2,
   "other_rejects": 7,
   "total_rejects": 17,
   "overall_pct": 0.6,
   "g2_roundness_pct": 0.5,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 7",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 11,
   "g1_roundness": 1,
   "other_rejects": 6,
   "total_rejects": 18,
   "overall_pct": 0.6,
   "g2_roundness_pct": 0.7,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 8",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 14,
   "g1_roundness": 2,
   "other_rejects": 7,
   "total_rejects": 23,
   "overall_pct": 0.8,
   "g2_roundness_pct": 0.9,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 9",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 19,
   "g1_roundness": 1,
   "other_rejects": 6,
   "total_rejects": 26,
   "overall_pct": 0.9,
   "g2_roundness_pct": 1.3,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 10",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 25,
   "g1_roundness": 2,
   "other_rejects": 7,
   "total_rejects": 34,
   "overall_pct": 1.1,
   "g2_roundness_pct": 1.7,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 11",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 31,
   "g1_roundness": 1,
   "other_rejects": 6,
   "total_rejects": 38,
   "overall_pct": 1.3,
   "g2_roundness_pct": 2.1,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 12",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 38,
   "g1_roundness": 2,
   "other_rejects": 7,
   "total_rejects": 47,
   "overall_pct": 1.6,
   "g2_roundness_pct": 2.5,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 13",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 46,
   "g1_roundness": 1,
   "other_rejects": 6,
   "total_rejects": 53,
   "overall_pct": 1.8,
   "g2_roundness_pct": 3.1,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 14",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 53,
   "g1_roundness": 2,
   "other_rejects": 7,
   "total_rejects": 62,
   "overall_pct": 2.1,
   "g2_roundness_pct": 3.5,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 15",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 60,
   "g1_roundness": 1,
   "other_rejects": 6,
   "total_rejects": 67,
   "overall_pct": 2.2,
   "g2_roundness_pct": 4.0,
   "g1_roundness_pct": 0.1
  },
  {
   "week": "Wk 16",
   "completions": 3000,
   "g2_completions": 1500,
   "g1_completions": 1500,
   "g2_roundness": 66,
   "g1_roundness": 2,
   "other_rejects": 7,
   "total_rejects": 75,
   "overall_pct": 2.5,
   "g2_roundness_pct": 4.4,
   "g1_roundness_pct": 0.1
  }
 ],
 "focus_month": {
  "week": "Wk 16",
  "total_rejects": 75,
  "completions": 3000,
  "overall_pct": 2.5,
  "defect_types": [
   {
    "type": "Roundness",
    "rejects": 68
   },
   {
    "type": "Diameter out of tolerance",
    "rejects": 3
   },
   {
    "type": "Surface finish",
    "rejects": 2
   },
   {
    "type": "Taper",
    "rejects": 2
   }
  ]
 },
 "by_machine": [
  {
   "machine": "G-1",
   "completions": 1500,
   "roundness_rejects": 2,
   "pct": 0.1
  },
  {
   "machine": "G-2",
   "completions": 1500,
   "roundness_rejects": 66,
   "pct": 4.4
  }
 ],
 "g2_strata": {
  "shift": [
   {
    "name": "Shift A",
    "rejects": 33,
    "completions": 750
   },
   {
    "name": "Shift B",
    "rejects": 33,
    "completions": 750
   }
  ],
  "operator": [
   {
    "name": "Operator 1",
    "rejects": 22,
    "completions": 510
   },
   {
    "name": "Operator 2",
    "rejects": 22,
    "completions": 495
   },
   {
    "name": "Operator 3",
    "rejects": 22,
    "completions": 495
   }
  ],
  "part_number": [
   {
    "name": "PS-24",
    "rejects": 40,
    "completions": 900
   },
   {
    "name": "PS-31",
    "rejects": 16,
    "completions": 375
   },
   {
    "name": "VS-12",
    "rejects": 10,
    "completions": 225
   }
  ],
  "worst_journal": [
   {
    "name": "J1",
    "rejects": 22
   },
   {
    "name": "J2",
    "rejects": 22
   },
   {
    "name": "J3",
    "rejects": 22
   }
  ],
  "all_journals_over": 63
 },
 "g2_reject_shafts": [
  {
   "shaft": "G2-W16-1266",
   "J1": 3.7,
   "J2": 2.8,
   "J3": 2.7
  },
  {
   "shaft": "G2-W16-1855",
   "J1": 2.6,
   "J2": 3.8,
   "J3": 2.8
  },
  {
   "shaft": "G2-W16-1264",
   "J1": 2.8,
   "J2": 2.3,
   "J3": 3.2
  },
  {
   "shaft": "G2-W16-1901",
   "J1": 3.9,
   "J2": 3.5,
   "J3": 3.5
  },
  {
   "shaft": "G2-W16-1469",
   "J1": 3.1,
   "J2": 3.2,
   "J3": 3.0
  },
  {
   "shaft": "G2-W16-1093",
   "J1": 3.6,
   "J2": 3.5,
   "J3": 3.7
  },
  {
   "shaft": "G2-W16-1840",
   "J1": 3.1,
   "J2": 3.0,
   "J3": 3.0
  },
  {
   "shaft": "G2-W16-1546",
   "J1": 3.3,
   "J2": 3.7,
   "J3": 3.3
  },
  {
   "shaft": "G2-W16-1236",
   "J1": 3.0,
   "J2": 3.1,
   "J3": 3.2
  },
  {
   "shaft": "G2-W16-1159",
   "J1": 3.7,
   "J2": 3.3,
   "J3": 3.6
  },
  {
   "shaft": "G2-W16-1827",
   "J1": 3.4,
   "J2": 3.7,
   "J3": 3.5
  },
  {
   "shaft": "G2-W16-1942",
   "J1": 3.2,
   "J2": 3.4,
   "J3": 3.7
  },
  {
   "shaft": "G2-W16-1718",
   "J1": 3.4,
   "J2": 3.2,
   "J3": 3.1
  },
  {
   "shaft": "G2-W16-1412",
   "J1": 3.7,
   "J2": 3.8,
   "J3": 3.3
  },
  {
   "shaft": "G2-W16-1401",
   "J1": 3.7,
   "J2": 3.5,
   "J3": 3.9
  },
  {
   "shaft": "G2-W16-1902",
   "J1": 3.2,
   "J2": 3.1,
   "J3": 3.1
  },
  {
   "shaft": "G2-W16-1029",
   "J1": 3.2,
   "J2": 3.5,
   "J3": 3.4
  },
  {
   "shaft": "G2-W16-1182",
   "J1": 3.7,
   "J2": 3.8,
   "J3": 3.9
  },
  {
   "shaft": "G2-W16-1552",
   "J1": 3.7,
   "J2": 3.5,
   "J3": 3.4
  },
  {
   "shaft": "G2-W16-1977",
   "J1": 3.2,
   "J2": 3.4,
   "J3": 3.1
  },
  {
   "shaft": "G2-W16-1059",
   "J1": 3.0,
   "J2": 3.0,
   "J3": 3.3
  },
  {
   "shaft": "G2-W16-1250",
   "J1": 3.9,
   "J2": 3.8,
   "J3": 3.6
  },
  {
   "shaft": "G2-W16-1727",
   "J1": 3.0,
   "J2": 3.1,
   "J3": 3.0
  },
  {
   "shaft": "G2-W16-1350",
   "J1": 3.5,
   "J2": 3.2,
   "J3": 3.7
  },
  {
   "shaft": "G2-W16-1197",
   "J1": 3.8,
   "J2": 3.3,
   "J3": 3.6
  },
  {
   "shaft": "G2-W16-1793",
   "J1": 3.0,
   "J2": 3.2,
   "J3": 3.1
  },
  {
   "shaft": "G2-W16-1518",
   "J1": 3.1,
   "J2": 3.1,
   "J3": 3.3
  },
  {
   "shaft": "G2-W16-1712",
   "J1": 3.3,
   "J2": 3.2,
   "J3": 3.1
  },
  {
   "shaft": "G2-W16-1673",
   "J1": 3.2,
   "J2": 3.5,
   "J3": 3.4
  },
  {
   "shaft": "G2-W16-1685",
   "J1": 3.3,
   "J2": 3.3,
   "J3": 3.4
  },
  {
   "shaft": "G2-W16-1359",
   "J1": 5.7,
   "J2": 5.1,
   "J3": 5.4
  },
  {
   "shaft": "G2-W16-1195",
   "J1": 5.3,
   "J2": 5.8,
   "J3": 5.7
  },
  {
   "shaft": "G2-W16-1298",
   "J1": 4.6,
   "J2": 4.6,
   "J3": 4.7
  },
  {
   "shaft": "G2-W16-1666",
   "J1": 5.8,
   "J2": 5.5,
   "J3": 5.3
  },
  {
   "shaft": "G2-W16-1324",
   "J1": 4.1,
   "J2": 4.2,
   "J3": 4.0
  },
  {
   "shaft": "G2-W16-1629",
   "J1": 4.1,
   "J2": 3.7,
   "J3": 4.2
  },
  {
   "shaft": "G2-W16-1286",
   "J1": 5.3,
   "J2": 5.0,
   "J3": 4.8
  },
  {
   "shaft": "G2-W16-1395",
   "J1": 5.5,
   "J2": 5.6,
   "J3": 5.3
  },
  {
   "shaft": "G2-W16-1496",
   "J1": 5.3,
   "J2": 5.5,
   "J3": 5.6
  },
  {
   "shaft": "G2-W16-1476",
   "J1": 5.9,
   "J2": 5.7,
   "J3": 5.4
  },
  {
   "shaft": "G2-W16-1057",
   "J1": 5.6,
   "J2": 5.7,
   "J3": 5.2
  },
  {
   "shaft": "G2-W16-1204",
   "J1": 4.4,
   "J2": 4.1,
   "J3": 4.6
  },
  {
   "shaft": "G2-W16-1249",
   "J1": 5.5,
   "J2": 5.1,
   "J3": 5.2
  },
  {
   "shaft": "G2-W16-1646",
   "J1": 5.6,
   "J2": 5.8,
   "J3": 5.3
  },
  {
   "shaft": "G2-W16-1346",
   "J1": 3.7,
   "J2": 3.8,
   "J3": 4.2
  },
  {
   "shaft": "G2-W16-1495",
   "J1": 5.0,
   "J2": 4.7,
   "J3": 4.9
  },
  {
   "shaft": "G2-W16-1257",
   "J1": 3.9,
   "J2": 4.3,
   "J3": 4.0
  },
  {
   "shaft": "G2-W16-1310",
   "J1": 4.2,
   "J2": 3.9,
   "J3": 4.3
  },
  {
   "shaft": "G2-W16-1243",
   "J1": 5.0,
   "J2": 4.8,
   "J3": 4.9
  },
  {
   "shaft": "G2-W16-1810",
   "J1": 5.0,
   "J2": 5.3,
   "J3": 4.9
  },
  {
   "shaft": "G2-W16-1097",
   "J1": 7.5,
   "J2": 7.8,
   "J3": 7.9
  },
  {
   "shaft": "G2-W16-1473",
   "J1": 6.3,
   "J2": 5.9,
   "J3": 5.9
  },
  {
   "shaft": "G2-W16-1587",
   "J1": 6.6,
   "J2": 7.0,
   "J3": 6.4
  },
  {
   "shaft": "G2-W16-1176",
   "J1": 7.6,
   "J2": 7.8,
   "J3": 7.9
  },
  {
   "shaft": "G2-W16-1902",
   "J1": 7.5,
   "J2": 7.3,
   "J3": 7.2
  },
  {
   "shaft": "G2-W16-1564",
   "J1": 7.0,
   "J2": 7.1,
   "J3": 6.8
  },
  {
   "shaft": "G2-W16-1378",
   "J1": 6.4,
   "J2": 6.4,
   "J3": 6.5
  },
  {
   "shaft": "G2-W16-1790",
   "J1": 7.2,
   "J2": 7.0,
   "J3": 6.7
  },
  {
   "shaft": "G2-W16-1154",
   "J1": 6.4,
   "J2": 6.5,
   "J3": 6.3
  },
  {
   "shaft": "G2-W16-1542",
   "J1": 9.2,
   "J2": 9.0,
   "J3": 9.3
  },
  {
   "shaft": "G2-W16-1635",
   "J1": 9.3,
   "J2": 9.0,
   "J3": 8.9
  },
  {
   "shaft": "G2-W16-1294",
   "J1": 8.5,
   "J2": 8.8,
   "J3": 8.4
  },
  {
   "shaft": "G2-W16-1900",
   "J1": 9.5,
   "J2": 9.2,
   "J3": 9.6
  },
  {
   "shaft": "G2-W16-1603",
   "J1": 11.6,
   "J2": 11.1,
   "J3": 11.3
  },
  {
   "shaft": "G2-W16-1104",
   "J1": 10.9,
   "J2": 11.4,
   "J3": 11.1
  },
  {
   "shaft": "G2-W16-1922",
   "J1": 13.2,
   "J2": 12.8,
   "J3": 13.3
  }
 ],
 "histogram": {
  "bins": [
   "0-1",
   "1-2",
   "2-3",
   "3-4",
   "4-6",
   "6-8",
   "8-10",
   "10-14"
  ],
  "g1": [
   600,
   775,
   123,
   2,
   0,
   0,
   0,
   0
  ],
  "g2": [
   300,
   780,
   354,
   30,
   20,
   9,
   4,
   3
  ]
 },
 "incoming_vs_outgoing": {
  "g1": {
   "incoming_um": 21,
   "outgoing_median_um": 1.4
  },
  "g2": {
   "incoming_um": 20,
   "outgoing_median_um": 2.1,
   "outgoing_p95_um": 2.9
  }
 },
 "traces": {
  "accepted": {
   "machine": "G-1",
   "shaft": "G1-W16-2231",
   "journals": {
    "J1": {
     "roundness_um": 1.6,
     "lobes": 0
    },
    "J2": {
     "roundness_um": 1.8,
     "lobes": 0
    },
    "J3": {
     "roundness_um": 1.7,
     "lobes": 0
    }
   }
  },
  "reject": {
   "machine": "G-2",
   "shaft": "G2-W16-1104",
   "journals": {
    "J1": {
     "roundness_um": 10.9,
     "lobes": 2
    },
    "J2": {
     "roundness_um": 11.4,
     "lobes": 2
    },
    "J3": {
     "roundness_um": 11.1,
     "lobes": 2
    }
   }
  }
 },
 "lobe_analysis": {
  "traces_reviewed": 60,
  "two_lobe": 47,
  "three_lobe": 9,
  "five_plus": 4,
  "note": "Lobe count recorded as observed on the polar trace; interpretation belongs to root cause analysis"
 },
 "sources": {
  "S1": "MS-02 weekly first-cycle record, weeks 1-16: 3,000 completions per week (1,500 per machine); total rejects, roundness rejects by machine, and other reject codes as tabulated. Overall rate = total rejects / completions. Site quality plan QP-24 sets ≤0.5%.",
  "S2": "Drawing PS-24 rev D note 4: roundness ≤3 µm per journal, least-squares circle, peak-to-valley. MS-02 gauge expanded uncertainty ±0.3 µm.",
  "S3": "MS-02 record for week 16 stratified by machine, shift, operator, part number and worst journal. Same incoming lots were split between G-1 and G-2 throughout. On rejected shafts, all three journals were over the limit in 97 of 102 cases.",
  "S4": "Polar traces exported from MS-02 for shaft G1-W16-2231 (accepted: J1 1.6, J2 1.8, J3 1.7 µm) and G2-W16-1104 (rejected: J1 10.9, J2 11.4, J3 11.1 µm, all two-lobe with the lobes at the same angular position on each journal), week 16, day 3.",
  "S5": "Roundness value distribution, all week-16 completions by machine, from MS-02 export; bins as shown.",
  "S6": "Incoming blank roundness sample log, weeks 12-16: 40 blanks per machine per week, 18-24 µm, no difference between machines.",
  "S7": "Lobe count review of 60 randomly selected G-2 reject traces, weeks 14-16: 47 two-lobe, 9 three-lobe, 4 five-or-more.",
  "S8": "Spindle runout check sheet, week 16: dial test indicator on the spindle at the standard check point, 50 mm from the housing face, G-1 and G-2, spindle at 3,000 rpm after 30 min warm-up; total indicator reading, once per revolution. Machine limit ≤2 µm.",
  "S9": "Spindlehead grease analysis, week 16: G-2 front bearing pair raceways pitted, grease milky; rear pair clean. Grease samples from front and rear cavities of both machines, water content by Karl Fischer titration; grease maker's limit 1 %.",
  "S10": "Wheelhead section drawing and observation log, week 16: coolant seen pooling on the G-2 nose after each cycle stop; labyrinth is non-contact and relies on the air curtain (barrier air) from the housing port to keep the flow outward; coolant runs 20 s after spindle stop on both machines.",
  "S11": "Barrier air check, week 16: gauge at the seal port, G-1 0.4 bar, G-2 0.1 bar. Barrier air line layout: one supply and regulator set for G-1, low-pressure switch at the supply ahead of the G-1 branch, G-2 branch in series downstream.",
  "S12": "Grinder builder's manual: barrier air at the spindle seal 0.3–0.5 bar, one air connection per machine. Plant procurement specification and installation acceptance record: no requirement for a regulator at each machine, no pressure measured at the seal ports. Grinder PM checklist: supply switch and gauge only, passed every month.",
  "S13": "Restart record, week 17: G-2 front bearing pair replaced, cavity flushed, regreased; runout at the standard check point 0.7 µm. Regulator and gauge fitted at each machine; port readings G-1 0.40 bar, G-2 0.35 bar. G-1 weekly roundness rejects during containment 0.1 %.",
  "S14": "Controls change record, weeks 18–19: low-pressure switch at each seal port wired to the machine controller, trip tested by bleeding each port to 0.25 bar (no start; stop and andon during run); stop sequence coolant off 10 s before spindle stop, barrier air held 15 min after stop, timer log.",
  "S15": "Documents issued weeks 17–20: equipment specification ES-114 rev C (per-machine air conditioning per builder manual); installation acceptance checklist IA-07 rev B; grinder daily check sheet rev 4; PM plan revision (grease water content six-monthly, runout quarterly); MS-02 weekly roundness chart with 0.5 % action limit per machine.",
  "S16": "MS-02 weekly record, weeks 17–24: first-pass rejects by machine (roundness and other), completions by machine; G-2 restarted week 17 after the bearing change with 500 completions that week. Polar traces exported from MS-02, week 24, day 3, J2 on one shaft from each machine.",
  "S17": "Documents issued weeks 17–20 with revision numbers: ES-114 rev C, IA-07 rev B, grinder daily check rev 4, PM plan G-1/G-2, controller standard CS-G, MS-02 weekly chart with action limit.",
  "S18": "Change point management sheet, final-grind area, week 21: change points on a grinder that trigger a check before restart, with the check, the owner and the watch period.",
  "S19": "Horizontal deployment audit, weeks 21–23: every machine on site with a spindle seal, seal type, barrier air feed, pressure at the port, action and completion week."
 },
 "operation": "G-1 and G-2 are CNC cylindrical grinders. Each shaft is held between centers and all three journals are ground in one setup by the same wheel and wheel spindle, in three sequential plunge grinds (J1, J2, J3). Both machines run the same program, wheel specification and coolant supply.",
 "period_unit": "week",
 "process_flow": [
  {
   "id": "turn",
   "label": "TURN",
   "sub": "blank to size"
  },
  {
   "id": "heat-treat",
   "label": "HEAT TREAT",
   "sub": "harden journals"
  },
  {
   "id": "final-grind",
   "label": "FINAL GRIND",
   "sub": "G-1 · G-2",
   "role": "focus",
   "detail": {
    "title": "Final grind · G-1 and G-2",
    "items": [
     "Two CNC cylindrical grinders, G-1 and G-2, same program, wheel specification and coolant supply",
     "Each shaft held between centers; journals J1, J2, J3 ground in one setup by the same wheel and wheel spindle, three sequential plunge grinds",
     "Incoming blanks sampled at receipt: typically 18–24 µm roundness on both machines, same lots split between G-1 and G-2"
    ],
    "source": "S1"
   }
  },
  {
   "id": "ms-02",
   "label": "MS-02",
   "sub": "roundness · every shaft",
   "role": "station",
   "detail": {
    "title": "MS-02 in-line roundness gauge",
    "items": [
     "Immediately after final grind, before wash and pack",
     "Every shaft leaving G-1 or G-2 measured on all three journals; 100% coverage",
     "Record: shaft ID, machine, shift, operator, part number, week and day, roundness per journal, worst journal, primary reject code",
     "Reject rate = unique shafts rejected on first measurement ÷ all unique first-cycle completions in the period; rechecks and rework excluded"
    ],
    "source": "S1"
   }
  },
  {
   "id": "wash-pack",
   "label": "WASH · PACK",
   "sub": "to stock"
  }
 ],
 "target": {
  "metric": "final-grind first-pass rejects",
  "from_pct": 2.5,
  "to": "≤0.5%",
  "by": "Wk 20",
  "feature": "every journal within 3 µm"
 },
 "root_cause": {
  "rungs": [
   {
    "id": "runout",
    "claim": "Why are the G-2 journals out of round? Because the grinding wheel spindle has excessive runout: 4.8 µm against the 2 µm limit.",
    "measure": "Wheel-spindle radial runout",
    "unit": "µm",
    "std": 2.0,
    "std_label": "≤2 µm machine limit",
    "g1": 0.6,
    "g2": 4.8,
    "method": "Dial test indicator on the spindle at the standard check point, 50 mm from the housing face, spindle at grinding speed after 30 min warm-up, week 16. Total indicator reading, once per revolution.",
    "source": "S8"
   },
   {
    "id": "bearing",
    "claim": "Why does the spindle have excessive runout? Because the front bearing pair is worn: raceways pitted, radial play in the pair. The rear pair is sound.",
    "findings": [
     [
      "Front bearing pair",
      "raceways pitted · grease milky · radial play"
     ],
     [
      "Rear bearing pair",
      "clean · no play"
     ]
    ],
    "method": "Spindlehead inspection, week 16, G-2.",
    "source": "S9"
   },
   {
    "id": "grease",
    "claim": "Why is the front bearing pair worn? Because coolant is in its grease: emulsified grease no longer carries load and the raceways pit. Ingress is small per cycle; water builds over years until the film fails, then wear accelerates.",
    "measure": "Water content, front-bearing grease",
    "unit": "%",
    "std": 1.0,
    "std_label": "≤1 % grease maker limit",
    "g1": 0.3,
    "g2": 6.8,
    "method": "Spindlehead grease analysis, week 16: water content by Karl Fischer titration, front and rear cavities, both machines.",
    "source": "S9"
   },
   {
    "id": "path",
    "claim": "Why is coolant in the grease? Because a small amount passes through the labyrinth seal at every stop: as the housing cools, the cavity pressure drops and draws pooled coolant and mist through the clearance.",
    "source": "S10"
   },
   {
    "id": "switch",
    "claim": "Why does coolant pass through the labyrinth? Because the air curtain (barrier air) at the G-2 seal is too weak, 0.1 bar against the 0.3 bar it needs: G-2 is fed in series from the one regulator, set to give G-1 its 0.4 bar, and the pressure falls along the branch.",
    "source": "S11"
   }
  ],
  "cleared": [
   {
    "suspect": "Coolant supply and nozzles",
    "evidence": "Shared tank, same concentration; nozzle settings unchanged on both machines since installation"
   },
   {
    "suspect": "Wheel balance",
    "evidence": "Residual 0.3 µm on both machines, week 16"
   },
   {
    "suspect": "Dressing",
    "evidence": "Fresh dress on G-2 left the roundness error unchanged"
   },
   {
    "suspect": "Workhead centers",
    "evidence": "Center runout 0.4 µm G-2, 0.5 µm G-1"
   },
   {
    "suspect": "Grease life and crash",
    "evidence": "Same grease and interval as G-1; no crash record; wear progressive, not sudden"
   }
  ],
  "air_line": {
   "switch_at": "supply, ahead of G-1",
   "g1_bar": 0.4,
   "g2_bar": 0.1,
   "spec_bar": 0.3,
   "regulator": "one regulator · set for G-1"
  },
  "occurrence": "Each grinder has one air connection, and the builder's manual states the barrier air pressure required at the seal, 0.3 to 0.5 bar. At installation both machines were fed from one regulator, set to give G-1 its pressure. The plant's procurement specification and installation acceptance did not require a regulator at each machine or a pressure check at each seal port.",
  "escape": "The line's only low-pressure switch sits on the supply ahead of G-1. It reads G-1's pressure and never sees the G-2 branch, so no fault tripped and every PM passed."
 },
 "countermeasures": {
  "kinds": {
   "restore": "Restore",
   "prevent": "Prevent recurrence",
   "detect": "Detect",
   "temporary": "Temporary"
  },
  "items": [
   {
    "n": 1,
    "answers": "Why 1–2",
    "text": "Replace G-2 front bearing pair, flush the cavity, regrease; verify runout ≤2 µm at the standard check point",
    "kind": "restore",
    "owner": "Maintenance",
    "due": "Wk 17"
   },
   {
    "n": 2,
    "answers": "Why 5",
    "text": "Regulator at each machine, set 0.3–0.5 bar per builder manual; gauge at each seal port",
    "kind": "prevent",
    "owner": "Maintenance",
    "due": "Wk 17"
   },
   {
    "n": 3,
    "answers": "Escape",
    "text": "Low-pressure switch at each seal port wired to that machine's controller: no spindle start below 0.3 bar; alarm, stop and andon on loss during run",
    "kind": "detect",
    "owner": "Controls engineering",
    "due": "Wk 18"
   },
   {
    "n": 4,
    "answers": "Why 4",
    "text": "Stop-sequence standard: coolant off before spindle stop; barrier air held through cooldown by timer",
    "kind": "prevent",
    "owner": "Controls engineering",
    "due": "Wk 18"
   },
   {
    "n": 5,
    "answers": "Occurrence",
    "text": "Purchasing standard: equipment specification requires per-machine air conditioning per the builder manual",
    "kind": "prevent",
    "owner": "Purchasing · plant engineering",
    "due": "Wk 19"
   },
   {
    "n": 6,
    "answers": "Occurrence",
    "text": "Installation acceptance standard: pressure verified at every seal port, switch trip tested, both recorded",
    "kind": "prevent",
    "owner": "Plant engineering",
    "due": "Wk 19"
   },
   {
    "n": 7,
    "answers": "Why 3, 5",
    "text": "PM items: barrier air pressure at each port on the operator daily check, range marked on the gauge; grease water content at interval; spindle runout at interval",
    "kind": "detect",
    "owner": "Maintenance planner",
    "due": "Wk 18"
   },
   {
    "n": 8,
    "answers": "Escape",
    "text": "MS-02 roundness rejects trended per machine with an action limit, so a rise is acted on before the site limit is crossed",
    "kind": "detect",
    "owner": "Quality",
    "due": "Wk 17"
   }
  ],
  "deferred_to_step8": "Horizontal deployment: audit every other machine on site with barrier-air seals for the same series feed",
  "temporary": {
   "n": 0,
   "answers": "Customer",
   "text": "Containment: G-2 stopped from week 16; all PS-24 shafts ground on G-1; MS-02 stays at 100 % coverage",
   "kind": "temporary",
   "owner": "Production supervisor",
   "due": "Wk 16"
  },
  "options": [
   {
    "decision": "Barrier air at the G-2 seal (Why 5)",
    "considered": [
     {
      "text": "Raise the one regulator until G-2 reaches 0.3 bar",
      "verdict": "rejected · G-1 would run above the 0.5 bar maximum"
     },
     {
      "text": "Separate air line from the supply to G-2",
      "verdict": "rejected · new pipe run, same single switch problem"
     },
     {
      "text": "Regulator and gauge at each machine",
      "verdict": "chosen · each seal set independently, checked at the port"
     }
    ]
   },
   {
    "decision": "Catching a loss of barrier air (escape)",
    "considered": [
     {
      "text": "Gauge at each port on the daily check only",
      "verdict": "rejected · administrative; a loss between checks runs unseen"
     },
     {
      "text": "Low-pressure switch at each port wired to the controller",
      "verdict": "chosen · no start below 0.3 bar, stop and andon on loss"
     }
    ]
   }
  ],
  "consensus": "Plan agreed week 17 by production, maintenance, quality, purchasing and plant engineering; temporary item first, permanent items behind it."
 },
 "implementation": {
  "weeks": [
   "Wk 16",
   "Wk 17",
   "Wk 18",
   "Wk 19",
   "Wk 20"
  ],
  "target_week": "Wk 20",
  "check": "Progress reviewed weekly at the production meeting: the maintenance manager reports each item, the plant engineering manager confirms it at the machine before it is marked done.",
  "items": [
   {
    "n": 0,
    "text": "Containment: G-2 stopped, all shafts on G-1",
    "planned": "Wk 16",
    "actual": "Wk 16",
    "confirmed": "G-1 weekly roundness rejects 0.1 %, weeks 16–17; MS-02 coverage 100 %",
    "source": "S13",
    "status": "done",
    "short": "Containment: all shafts on G-1"
   },
   {
    "n": 1,
    "text": "G-2 front bearing pair replaced, cavity flushed, regreased",
    "planned": "Wk 17",
    "actual": "Wk 17",
    "confirmed": "Runout at the standard check point 0.7 µm (limit ≤2 µm)",
    "source": "S13",
    "status": "done",
    "short": "G-2 bearing pair replaced"
   },
   {
    "n": 2,
    "text": "Regulator and gauge at each machine",
    "planned": "Wk 17",
    "actual": "Wk 17",
    "confirmed": "At the seal port: G-1 0.40 bar, G-2 0.35 bar (spec 0.3–0.5)",
    "source": "S13",
    "status": "done",
    "short": "Regulator and gauge at each machine"
   },
   {
    "n": 3,
    "text": "Low-pressure switch at each seal port, wired to the controller",
    "planned": "Wk 18",
    "actual": "Wk 19",
    "confirmed": "Trip test by bleeding each port to 0.25 bar: no spindle start; stop and andon during run. Switch delivery one week late",
    "source": "S14",
    "status": "late",
    "short": "Pressure switch at each seal port"
   },
   {
    "n": 4,
    "text": "Stop sequence: coolant off before spindle stop; barrier air held through cooldown",
    "planned": "Wk 18",
    "actual": "Wk 18",
    "confirmed": "Controller sequence: coolant off 10 s before spindle stop; barrier air held 15 min after stop, timer log checked",
    "source": "S14",
    "status": "done",
    "short": "Stop sequence in the controller"
   },
   {
    "n": 5,
    "text": "Purchasing standard: per-machine air conditioning per builder manual",
    "planned": "Wk 19",
    "actual": "Wk 20",
    "confirmed": "Equipment specification ES-114 rev C issued",
    "source": "S15",
    "status": "late",
    "short": "Purchasing standard issued"
   },
   {
    "n": 6,
    "text": "Installation acceptance: pressure at every seal port, switch trip tested",
    "planned": "Wk 19",
    "actual": "Wk 19",
    "confirmed": "Acceptance checklist IA-07 rev B issued",
    "source": "S15",
    "status": "done",
    "short": "Installation acceptance standard"
   },
   {
    "n": 7,
    "text": "PM items: daily port pressure check, grease water content, spindle runout",
    "planned": "Wk 18",
    "actual": "Wk 18",
    "confirmed": "Daily check sheet rev 4 with marked range; grease water content six-monthly; runout quarterly",
    "source": "S15",
    "status": "done",
    "short": "PM items added"
   },
   {
    "n": 8,
    "text": "MS-02 roundness rejects by machine with an action limit",
    "planned": "Wk 17",
    "actual": "Wk 17",
    "confirmed": "Weekly chart carries a 0.5 % action limit per machine; quality reviews it weekly",
    "source": "S15",
    "status": "done",
    "short": "MS-02 chart with action limit"
   }
  ]
 },
 "results": {
  "weeks_after": [
   {
    "week": "Wk 17",
    "g1_completions": 1500,
    "g1_roundness": 3,
    "g1_other": 3,
    "g2_completions": 500,
    "g2_roundness": 1,
    "g2_other": 1,
    "g1_pct": 0.4,
    "g2_pct": 0.4
   },
   {
    "week": "Wk 18",
    "g1_completions": 1500,
    "g1_roundness": 2,
    "g1_other": 3,
    "g2_completions": 1500,
    "g2_roundness": 3,
    "g2_other": 3,
    "g1_pct": 0.33,
    "g2_pct": 0.4
   },
   {
    "week": "Wk 19",
    "g1_completions": 1500,
    "g1_roundness": 1,
    "g1_other": 3,
    "g2_completions": 1500,
    "g2_roundness": 2,
    "g2_other": 3,
    "g1_pct": 0.27,
    "g2_pct": 0.33
   },
   {
    "week": "Wk 20",
    "g1_completions": 1500,
    "g1_roundness": 2,
    "g1_other": 3,
    "g2_completions": 1500,
    "g2_roundness": 1,
    "g2_other": 3,
    "g1_pct": 0.33,
    "g2_pct": 0.27
   },
   {
    "week": "Wk 21",
    "g1_completions": 1500,
    "g1_roundness": 1,
    "g1_other": 3,
    "g2_completions": 1500,
    "g2_roundness": 2,
    "g2_other": 3,
    "g1_pct": 0.27,
    "g2_pct": 0.33
   },
   {
    "week": "Wk 22",
    "g1_completions": 1500,
    "g1_roundness": 2,
    "g1_other": 3,
    "g2_completions": 1500,
    "g2_roundness": 1,
    "g2_other": 4,
    "g1_pct": 0.33,
    "g2_pct": 0.33
   },
   {
    "week": "Wk 23",
    "g1_completions": 1500,
    "g1_roundness": 1,
    "g1_other": 3,
    "g2_completions": 1500,
    "g2_roundness": 2,
    "g2_other": 3,
    "g1_pct": 0.27,
    "g2_pct": 0.33
   },
   {
    "week": "Wk 24",
    "g1_completions": 1500,
    "g1_roundness": 2,
    "g1_other": 3,
    "g2_completions": 1500,
    "g2_roundness": 1,
    "g2_other": 3,
    "g1_pct": 0.33,
    "g2_pct": 0.27
   }
  ],
  "marks": [
   [
    "Wk 17",
    "1 & 2"
   ],
   [
    "Wk 18",
    "4 & 7"
   ],
   [
    "Wk 19",
    "3 & 6"
   ],
   [
    "Wk 20",
    "5"
   ]
  ],
  "implemented_caption": "Implemented (Step 6 item numbers): Wk 17 bearings replaced (1), regulator and gauge at each machine (2); Wk 18 stop sequence (4), PM items (7); Wk 19 pressure switches (3), acceptance standard (6); Wk 20 purchasing standard (5).",
  "traces_after": {
   "week": "Wk 24",
   "day": 3,
   "g1": {
    "shaft": "G1-W24-2210",
    "J2": 1.7
   },
   "g2": {
    "shaft": "G2-W24-1132",
    "J2": 1.6
   }
  }
 },
 "standardize": {
  "standards": [
   {
    "doc": "ES-114 rev C",
    "what": "Equipment specification: per-machine air conditioning (regulator, gauge, low-pressure switch at the seal port) per builder manual",
    "owner": "Purchasing · plant engineering",
    "issued": "Wk 20"
   },
   {
    "doc": "IA-07 rev B",
    "what": "Installation acceptance: pressure measured at every seal port, switch trip tested, both recorded before sign-off",
    "owner": "Plant engineering",
    "issued": "Wk 19"
   },
   {
    "doc": "Grinder daily check, rev 4",
    "what": "Barrier air pressure at each seal port, range marked on the gauge, recorded by the operator each shift",
    "owner": "Production",
    "issued": "Wk 18"
   },
   {
    "doc": "PM plan G-1 / G-2",
    "what": "Grease water content six-monthly; spindle runout at the standard check point quarterly; switch trip test monthly",
    "owner": "Maintenance planner",
    "issued": "Wk 18"
   },
   {
    "doc": "Controller standard CS-G",
    "what": "Stop sequence: coolant off 10 s before spindle stop; barrier air held 15 min after stop",
    "owner": "Controls engineering",
    "issued": "Wk 18"
   },
   {
    "doc": "MS-02 weekly chart",
    "what": "Roundness rejects by machine with a 0.5 % action limit; quality reviews weekly",
    "owner": "Quality",
    "issued": "Wk 17"
   }
  ],
  "change_points": [
   {
    "change": "Spindle bearing replaced or spindle exchanged",
    "check": "Runout at the standard check point; grease sample at 3 months",
    "who": "Maintenance",
    "when": "Before restart · 3 months"
   },
   {
    "change": "Any work on the barrier air line, regulator or seal",
    "check": "Pressure at the seal port; switch trip test",
    "who": "Maintenance",
    "when": "Before restart"
   },
   {
    "change": "Coolant nozzle, pressure or concentration changed",
    "check": "Pressure at the seal port; MS-02 roundness by machine watched",
    "who": "Production · quality",
    "when": "Before restart · next 500 shafts"
   },
   {
    "change": "Controller program change on a grinder",
    "check": "Stop sequence timing verified",
    "who": "Controls engineering",
    "when": "Before restart"
   },
   {
    "change": "New grinder or relocated grinder",
    "check": "IA-07 rev B acceptance in full",
    "who": "Plant engineering",
    "when": "Before production"
   }
  ],
  "deployment": [
   {
    "machine": "G-3 · G-4",
    "where": "Final grind, valve spool line",
    "seal": "Labyrinth · barrier air",
    "found": "Series feed from one regulator; G-4 0.15 bar at the port",
    "action": "Regulator, gauge and switch at each machine",
    "status": "Wk 22 · done"
   },
   {
    "machine": "IG-1",
    "where": "Internal grind, bearing sleeves",
    "seal": "Labyrinth · barrier air",
    "found": "Own regulator; 0.35 bar at the port; no switch",
    "action": "Switch at the port, wired to the controller",
    "status": "Wk 23 · done"
   },
   {
    "machine": "CG-1",
    "where": "Centerless, pre-grind",
    "seal": "Contact seal · no barrier air",
    "found": "Not applicable",
    "action": "None",
    "status": "—"
   },
   {
    "machine": "L-1 · L-2",
    "where": "Turning",
    "seal": "Contact seal · no barrier air",
    "found": "Not applicable",
    "action": "None",
    "status": "—"
   }
  ]
 }
}