{ "opd": "benikigai/ec-1", "commit": 1, "opd_version": "0.4.0", "layer": "variants", "question": "What change would be better, and what does it cost?", "data": { "design_intent": { "targets": [ { "characteristic": "gap", "where": [ "part:top-shell" ], "target": { "value": 0.2, "unit": "mm", "source": "inferred", "confidence": "low" }, "lower": { "value": 0.1, "unit": "mm", "source": "inferred", "confidence": "low" }, "upper": { "value": 0.3, "unit": "mm", "source": "inferred", "confidence": "low" }, "priority": "should", "owner": "industrial-design", "rationale": "Even, tight seam at the shoulder buttons" }, { "characteristic": "button-force", "where": [ "part:button-cap" ], "target": { "value": 180, "unit": "gf", "source": "measured", "confidence": "medium" }, "lower": { "value": 150, "unit": "gf", "source": "measured", "confidence": "medium" }, "upper": { "value": 210, "unit": "gf", "source": "measured", "confidence": "medium" }, "priority": "should", "owner": "industrial-design", "rationale": "Crisp, light press" }, { "characteristic": "button-travel", "where": [ "part:button-cap" ], "target": { "value": 0.8, "unit": "mm", "source": "measured", "confidence": "medium" }, "lower": { "value": 0.6, "unit": "mm", "source": "measured", "confidence": "medium" }, "upper": { "value": 1, "unit": "mm", "source": "measured", "confidence": "medium" }, "priority": "nice", "owner": "industrial-design" }, { "characteristic": "weight", "where": [ "asm:ec-1" ], "target": { "value": 69, "unit": "g", "source": "measured", "confidence": "high" }, "upper": { "value": 74, "unit": "g", "source": "measured", "confidence": "high" }, "priority": "must", "owner": "product", "rationale": "Light enough for long sessions; set from the parts below" }, { "characteristic": "battery-life", "where": [ "part:battery" ], "target": { "value": 30, "unit": "h", "source": "inferred", "confidence": "medium" }, "lower": { "value": 25, "unit": "h", "source": "inferred", "confidence": "medium" }, "priority": "must", "owner": "product", "rationale": "A week of evenings on one charge" }, { "characteristic": "drop-height", "where": [ "asm:ec-1" ], "target": { "value": 1.2, "unit": "m", "source": "inferred", "confidence": "medium" }, "priority": "must", "owner": "reliability" }, { "characteristic": "thickness", "where": [ "asm:ec-1" ], "target": { "value": 22, "unit": "mm", "source": "measured", "confidence": "high" }, "upper": { "value": 23, "unit": "mm", "source": "measured", "confidence": "high" }, "priority": "should", "owner": "industrial-design" } ] }, "variants": { "objectives": [ { "metric": "yield.rty", "direction": "max" }, { "metric": "cost.cost_per_good_unit", "direction": "min" }, { "metric": "throughput.cycle_time", "direction": "min" } ], "constraints": [ "takt 36 s (2,000 units a day over two 10-hour shifts)", "headcount at most 12", "no single new tool over 25,000 USD" ], "baseline": { "scores": { "yield": { "fpy_by_station": { "sta:a2": { "value": 0.992, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" }, "sta:a3": { "value": 0.996, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" }, "sta:a4": { "value": 0.99, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" }, "sta:t1": { "value": 0.985, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" }, "sta:t2": { "value": 0.978, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" }, "sta:t3": { "value": 0.983, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" }, "sta:t4": { "value": 0.995, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" } }, "rty": { "value": 0.922, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "interval": [ 0.905, 0.935 ], "confidence": "low" }, "top_failure_modes": [ { "failure_mode": "ext:controller:stick-drift", "share": { "value": 0.24, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" }, "issue": "iss:stick-drift-flux", "pfmea": "fm:stick-flux" }, { "failure_mode": "connector-unseat", "share": { "value": 0.18, "origin": "simulated", "engine": "mujoco", "runs": 2000, "confidence": "low" }, "issue": "iss:battery-unseat", "pfmea": "fm:battery-unseat" }, { "failure_mode": "gap-flush", "share": { "value": 0.16, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" }, "issue": "iss:shoulder-gap", "pfmea": "fm:gap-high" } ] }, "throughput": { "cycle_time": { "value": 30, "unit": "s", "origin": "estimated", "engine": "analytic", "confidence": "low", "note": "slowest station from time studies; needs the discrete-event simulator" }, "takt": { "value": 36, "unit": "s", "origin": "estimated", "engine": "analytic", "confidence": "high" }, "bottleneck_station": "sta:t1", "headcount": 11 }, "cost": { "cost_per_good_unit": { "value": 1.92, "unit": "USD", "origin": "estimated", "engine": "analytic", "confidence": "low", "note": "conversion cost per good unit, including scrap and rework" } }, "experience": { "weight": { "value": 69.4, "unit": "g", "origin": "measured", "confidence": "medium", "evidence": [ "src:caliper-run-1" ] }, "gap_flush_consistency": { "value": 0.0493, "unit": "mm, 1 sigma", "origin": "measured", "confidence": "medium", "evidence": [ "src:caliper-run-1" ] }, "predicted_field_return_rate": { "value": 0.031, "origin": "estimated", "confidence": "low" }, "review_sentiment": { "value": 0.42, "unit": "-1 to 1", "origin": "measured", "engine": "review-analysis", "confidence": "low", "evidence": [ "src:reviews" ] } } }, "pareto": { "on_frontier": true } }, "candidates": [ { "id": "var:split-t1", "name": "Second RF shield box at T1", "kind": "equipment", "base": "baseline", "description": "Two shield boxes so flashing and RF test run in parallel", "changes": [ { "action": "add", "target": [ "sta:t1" ], "description": "Second shield box and BLE tester" } ], "generated_by": { "method": "agent", "engine": "analytic", "created": "2026-10-30" }, "scores": { "yield": { "rty": { "value": 0.922, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" } }, "throughput": { "cycle_time": { "value": 25, "unit": "s", "origin": "estimated", "engine": "analytic", "confidence": "low" }, "bottleneck_station": "sta:t2", "headcount": 11 }, "cost": { "cost_per_good_unit": { "value": 1.98, "unit": "USD", "origin": "estimated", "engine": "analytic", "confidence": "low" }, "capex": { "value": 9800, "unit": "USD", "origin": "estimated", "engine": "analytic", "confidence": "medium" } } }, "pareto": { "on_frontier": true } }, { "id": "var:stick-connector", "name": "FPC connector for the stick instead of hand soldering", "kind": "design-change", "base": "baseline", "description": "Stick module ships with a flex tail; a ZIF connector replaces six hand-soldered pins", "addresses": [ "iss:stick-drift-flux", "fm:stick-flux" ], "changes": [ { "action": "replace", "target": [ "op:stick-solder" ], "description": "Solder step becomes a connector mate" }, { "action": "modify", "target": [ "part:stick-module" ], "description": "Module with flex tail, +0.12 USD" } ], "generated_by": { "method": "agent", "engine": "monte-carlo", "created": "2026-10-30" }, "scores": { "yield": { "rty": { "value": 0.936, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "interval": [ 0.92, 0.95 ], "confidence": "low" } }, "throughput": { "cycle_time": { "value": 28, "unit": "s", "origin": "estimated", "engine": "analytic", "confidence": "low" }, "headcount": 11 }, "cost": { "cost_per_good_unit": { "value": 1.95, "unit": "USD", "origin": "estimated", "engine": "analytic", "confidence": "low" } }, "experience": { "predicted_field_return_rate": { "value": 0.019, "origin": "estimated", "confidence": "low" } } }, "pareto": { "on_frontier": true } }, { "id": "var:preload-close", "name": "Preload fixture and tug test for the battery connector", "kind": "fixture-sequence", "base": "baseline", "description": "Closing fixture holds the connector down; a 2 N tug test after mating", "addresses": [ "iss:battery-unseat", "fm:battery-unseat" ], "changes": [ { "action": "modify", "target": [ "op:close" ], "description": "Preload pad in the closing fixture" }, { "action": "modify", "target": [ "op:battery-mate" ], "description": "Add tug test" } ], "generated_by": { "method": "agent", "engine": "mujoco", "created": "2026-10-30" }, "scores": { "yield": { "rty": { "value": 0.932, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "interval": [ 0.915, 0.945 ], "confidence": "low" } }, "throughput": { "cycle_time": { "value": 31, "unit": "s", "origin": "estimated", "engine": "analytic", "confidence": "low" }, "headcount": 11 }, "cost": { "cost_per_good_unit": { "value": 1.96, "unit": "USD", "origin": "estimated", "engine": "analytic", "confidence": "low" } } }, "pareto": { "on_frontier": false, "dominated_by": [ "var:stick-connector" ] } }, { "id": "var:gap-tight", "name": "Tighten the shoulder gap to 0.10 mm", "kind": "design-change", "base": "baseline", "description": "Industrial design asks for a tighter, more premium seam", "design_intent": { "targets": [ { "characteristic": "gap", "where": [ "part:top-shell" ], "target": { "value": 0.1, "unit": "mm", "source": "inferred", "confidence": "low" }, "upper": { "value": 0.15, "unit": "mm", "source": "inferred", "confidence": "low" }, "priority": "should", "owner": "industrial-design" } ] }, "changes": [ { "action": "modify", "target": [ "part:top-shell" ], "description": "Tighter tool tolerance and a cooling change on the shoulder wall" } ], "generated_by": { "method": "agent", "engine": "monte-carlo", "created": "2026-10-30" }, "scores": { "yield": { "rty": { "value": 0.874, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "interval": [ 0.85, 0.895 ], "confidence": "low" } }, "throughput": { "cycle_time": { "value": 30, "unit": "s", "origin": "estimated", "engine": "analytic", "confidence": "low" } }, "cost": { "cost_per_good_unit": { "value": 2.6, "unit": "USD", "origin": "estimated", "engine": "analytic", "confidence": "low" } }, "experience": { "gap_flush_consistency": { "value": 0.03, "unit": "mm, 1 sigma", "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" }, "cosmetic_defect_rate": { "value": 0.061, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" } } }, "pareto": { "on_frontier": false, "dominated_by": [ "baseline", "var:split-t1", "var:stick-connector" ] } }, { "id": "var:connector-and-preload", "name": "Stick connector plus battery preload", "kind": "mixed", "base": "baseline", "description": "Both fixes together", "addresses": [ "iss:stick-drift-flux", "iss:battery-unseat" ], "changes": [ { "action": "replace", "target": [ "op:stick-solder" ], "description": "As var:stick-connector" }, { "action": "modify", "target": [ "op:close", "op:battery-mate" ], "description": "As var:preload-close" } ], "generated_by": { "method": "agent", "engine": "monte-carlo", "created": "2026-10-31" }, "scores": { "yield": { "rty": { "value": 0.947, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "interval": [ 0.93, 0.96 ], "confidence": "low" } }, "throughput": { "cycle_time": { "value": 31, "unit": "s", "origin": "estimated", "engine": "analytic", "confidence": "low" }, "headcount": 11 }, "cost": { "cost_per_good_unit": { "value": 1.99, "unit": "USD", "origin": "estimated", "engine": "analytic", "confidence": "low" } }, "ramp": { "changes_needed": { "value": 3, "origin": "estimated", "confidence": "medium" } } }, "pareto": { "on_frontier": true } } ], "recommended": { "variant": "var:connector-and-preload", "rationale": "Highest simulated yield, and it closes the two largest failure modes, which together make up 42% of fallout", "tradeoffs": "0.07 USD more per good unit and 1 s slower than baseline, still inside the 36 s takt; T1 stays the bottleneck" }, "tradeoffs": [ { "id": "tr:gap-tighten", "characteristic": "gap", "from": { "value": 0.2, "unit": "mm", "source": "inferred", "confidence": "low" }, "to": { "value": 0.1, "unit": "mm", "source": "inferred", "confidence": "low" }, "variant": "var:gap-tight", "against": "baseline", "yield_delta": { "value": -0.048, "unit": "RTY", "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" }, "cost_per_unit_delta": { "value": 0.68, "unit": "USD", "origin": "estimated", "engine": "analytic", "confidence": "low" }, "other_deltas": { "experience.cosmetic_defect_rate": { "value": 0.044, "origin": "simulated", "engine": "monte-carlo", "runs": 20000, "confidence": "low" } }, "experience_effect": "A tighter seam that reads as more premium, for about 5 points of yield and 0.68 USD a unit", "decision": { "status": "rejected", "by": "product (fictional)", "on": "2026-10-31", "note": "Not worth the yield at this price point" } } ], "engine_notes": "Yield and failure shares come from Monte Carlo over the measured spreads and MuJoCo drop runs. Cycle time and line balance are estimates until the discrete-event simulator exists." } } }