{ "opd": "benikigai/plus-one", "commit": 6, "opd_version": "0.5.0", "layer": "variants", "question": "What change would be better, and what does it cost?", "data": { "design_intent": { "targets": [ { "characteristic": "size", "where": [ "part:top-shell" ], "target": { "value": 55.4, "unit": "mm", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "upper": { "value": 55.4, "unit": "mm", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "priority": "must", "owner": "industrial-design", "rationale": "Approved exterior direction (2026-11-01): the diameter of a common magnetic phone charger, so the puck sits flush on one. Replaces the 57 mm concept. The CAD, the magnet ring, the lugs and plus-one-base@1 in this file are still sized for 57 mm and need rework" }, { "characteristic": "thickness", "where": [ "part:top-shell", "part:base" ], "target": { "value": 12, "unit": "mm", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "upper": { "value": 12, "unit": "mm", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "priority": "must", "owner": "industrial-design", "rationale": "Approved exterior direction (2026-11-01): 12.0 mm at most, including the button dome and the base. Replaces 9.5 mm. A 12 mm puck still needs a thinner cell than the stock one; the CAD in this file is still 9.5 mm" }, { "characteristic": "weight", "where": [ "part:base" ], "target": { "value": 28, "unit": "g", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "upper": { "value": 32, "unit": "g", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "priority": "should", "owner": "product", "rationale": "Light enough to hang on a phone or a bag" }, { "characteristic": "button-travel", "where": [ "part:plus-button" ], "target": { "value": 0.3, "unit": "mm", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "lower": { "value": 0.2, "unit": "mm", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "upper": { "value": 0.4, "unit": "mm", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "priority": "must", "owner": "product", "rationale": "Short, firm click you can find without looking" }, { "characteristic": "other", "where": [ "part:magnet-ring" ], "target": { "value": 8, "unit": "N", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "lower": { "value": 6, "unit": "N", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "priority": "must", "owner": "product", "rationale": "Magnetic hold on a phone mount. It stays put when a phone in a car mount hits a bump" }, { "characteristic": "other", "where": [ "part:base" ], "target": { "value": 30, "unit": "N", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "lower": { "value": 30, "unit": "N", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "priority": "must", "owner": "mechanical", "rationale": "Lug pull-out. The twist-lock lugs carry the load for clips, lanyards and bikes; the magnets only align" }, { "characteristic": "other", "where": [ "part:pogo-pad" ], "target": { "value": 300, "unit": "mA", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "upper": { "value": 300, "unit": "mA", "source": "inferred", "confidence": "low", "evidence": [ "src:design-brief" ], "note": "design target" }, "priority": "must", "owner": "electrical", "rationale": "Pogo pad current limit. A shorted module trips safely" } ] }, "variants": { "objectives": [ { "metric": "throughput.cycle_time", "direction": "min" }, { "metric": "cost.cost_per_good_unit", "direction": "min" } ], "constraints": [ "takt 60 s (design target)", "headcount at most 9", "no new station type beyond the brief" ], "baseline": { "scores": { "throughput": { "cycle_time": { "value": 56, "unit": "s", "origin": "estimated", "engine": "expert-estimate", "confidence": "low", "note": "slowest station from target cycle times; nothing built" }, "takt": { "value": 60, "unit": "s", "origin": "estimated", "engine": "expert-estimate", "confidence": "medium", "note": "design target, about 480 units an 8-hour shift" }, "bottleneck_station": "sta:s8", "headcount": 8 } } }, "candidates": [ { "id": "var:bench-cell", "name": "Bench cell, for the first 100 builder units", "kind": "staffing", "base": "baseline", "description": "Decision 25's layout for the Q1 2027 bench builds. Three benches in a small U, no conveyor, at most three units in the cell. One technician carries each unit through: bench A does S1 to S4, bench B does S5 and S6, bench C does S7 and S8. 100 units in five build days. Layout: line/layouts/bench-cell.json.", "changes": [ { "action": "merge", "target": [ "sta:s1", "sta:s2", "sta:s3", "sta:s4" ], "description": "bench A" }, { "action": "merge", "target": [ "sta:s5", "sta:s6" ], "description": "bench B" }, { "action": "merge", "target": [ "sta:s7", "sta:s8" ], "description": "bench C" } ], "generated_by": { "method": "agent", "engine": "discrete-event", "run": "nplus1labs/factory 9bc6753 engine/examples/plus-one-demand", "created": "2026-11-02" }, "scores": { "throughput": { "takt": { "value": 1215, "unit": "s", "origin": "estimated", "engine": "analytic", "confidence": "medium", "note": "set by the assumed volume: one 8-hour shift less breaks, 21 working days a month" }, "uph": { "value": 16.9, "unit": "good units/h", "origin": "simulated", "engine": "discrete-event", "confidence": "low", "note": "capacity, simulated from assumed values; uncalibrated; no unit built; the technician is the constraint, not a bench; about 17% busy at this volume", "runs": 2000, "evidence": [ "src:factory-engine", "src:layout-study" ] }, "headcount": 1 } } }, { "id": "var:u-cell", "name": "U cell, for about 2,000 to 4,500 a month", "kind": "staffing", "base": "baseline", "description": "Decision 25's bridge between the bench builds and volume. The eight stations as benches in a U with a 2 s hand pass. Two operators: one runs S1 to S6, the other runs S7 and S8. Layout: line/layouts/u-cell.json.", "changes": [ { "action": "modify", "target": [ "sta:s1", "sta:s2", "sta:s3", "sta:s4", "sta:s5", "sta:s6" ], "description": "one operator walks S1 to S6" }, { "action": "modify", "target": [ "sta:s7", "sta:s8" ], "description": "a second operator runs S7 and S8" } ], "generated_by": { "method": "agent", "engine": "discrete-event", "run": "nplus1labs/factory 9bc6753 engine/examples/plus-one-demand", "created": "2026-11-02" }, "scores": { "throughput": { "takt": { "value": 255.15, "unit": "s", "origin": "estimated", "engine": "analytic", "confidence": "medium", "note": "set by the assumed volume: one 8-hour shift less breaks, 21 working days a month" }, "uph": { "value": 31.6, "unit": "good units/h", "origin": "simulated", "engine": "discrete-event", "confidence": "low", "note": "capacity, simulated from assumed values; uncalibrated; no unit built; the operator on S1 to S6 is the constraint", "runs": 2000, "evidence": [ "src:factory-engine", "src:layout-study" ] }, "headcount": 2 } } }, { "id": "var:madecell-balanced", "name": "Balanced MadeCell line, for about 10,000 a month", "kind": "mixed", "base": "baseline", "description": "Decision 24's MadeCell base (a 40 x 8 ft frame, four bays, stations facing out from a central conveyor, operators on the floor outside), balanced for decision 25's volume case. 16 pallets and an overhead restocking rail. S1 and S2 share a workstation, as do S3 and S4; S5 and S6 and S7 each run twice; S8 becomes a cell of three test fixtures. Seven people. Layout: line/layouts/madecell-balanced.json.", "changes": [ { "action": "merge", "target": [ "sta:s1", "sta:s2" ], "description": "workstation W1" }, { "action": "merge", "target": [ "sta:s3", "sta:s4" ], "description": "workstation W2" }, { "action": "split", "target": [ "sta:s5", "sta:s6" ], "description": "W3, built twice" }, { "action": "split", "target": [ "sta:s7" ], "description": "W4, built twice" }, { "action": "split", "target": [ "sta:s8" ], "description": "a test cell of three fixtures" } ], "generated_by": { "method": "agent", "engine": "discrete-event", "run": "nplus1labs/factory 9bc6753 engine/examples/plus-one-demand", "created": "2026-11-02" }, "scores": { "throughput": { "takt": { "value": 51.03, "unit": "s", "origin": "estimated", "engine": "analytic", "confidence": "medium", "note": "set by the assumed volume: one 8-hour shift less breaks, 21 working days a month" }, "uph": { "value": 88.8, "unit": "good units/h", "origin": "simulated", "engine": "discrete-event", "confidence": "low", "note": "capacity, simulated from assumed values; uncalibrated; no unit built; W1 (S1 and S2) is the bottleneck, about 79% busy", "runs": 2000, "evidence": [ "src:factory-engine", "src:layout-study" ] }, "headcount": 7, "bottleneck_station": "sta:s1" } } }, { "id": "var:split-s8", "name": "Split S8: test in one station, mark and pack in another", "kind": "station-layout", "base": "baseline", "description": "A ninth bench takes the laser mark and pack off S8. S7 and S8 then both sit at 40 s.", "changes": [ { "action": "add", "target": [ "sta:s8" ], "description": "mark and pack move to a new bench after S8" } ], "generated_by": { "method": "agent", "engine": "expert-estimate", "created": "2026-11-01" }, "scores": { "throughput": { "cycle_time": { "value": 40, "unit": "s", "origin": "estimated", "engine": "expert-estimate", "confidence": "low" }, "bottleneck_station": "sta:s7", "headcount": 9 } } }, { "id": "var:plus-one-plus", "name": "Plus One+ (coming next)", "kind": "design-change", "base": "baseline", "description": "Coming next. The same board with more parts fitted: light sensor, NFC tag, debug jumper; a clear shell option. No new station: a board-variant BOM at S2 and extra checks at S8, which push S8 past takt unless it is split.", "changes": [ { "action": "add", "target": [ "part:light-sensor", "part:nfc-tag", "part:debug-jumper" ], "description": "fit the empty footprints" }, { "action": "modify", "target": [ "sta:s8" ], "description": "add NFC and light-sensor checks" } ], "generated_by": { "method": "manual", "engine": "expert-estimate", "created": "2026-11-01" }, "scores": { "throughput": { "cycle_time": { "value": 62, "unit": "s", "origin": "estimated", "engine": "expert-estimate", "confidence": "low", "note": "S8 gains about 6 s of checks" }, "bottleneck_station": "sta:s8", "headcount": 8 } } }, { "id": "var:plus-one-plus-plus", "name": "Plus One++ (coming next)", "kind": "routing", "base": "var:plus-one-plus", "description": "Coming next. Plus One+ boxed with a set of backs. Adds S9 after S8, kitting the backs into the box.", "changes": [ { "action": "add", "target": [ "sta:s8" ], "description": "a new S9 after S8 kits the backs into a bigger box" } ], "generated_by": { "method": "manual", "engine": "expert-estimate", "created": "2026-11-01" }, "scores": { "throughput": { "cycle_time": { "value": 62, "unit": "s", "origin": "estimated", "engine": "expert-estimate", "confidence": "low", "note": "S9 kitting runs in parallel; S8 stays the bottleneck" }, "bottleneck_station": "sta:s8", "headcount": 9 } } } ], "recommended": { "variant": "var:bench-cell", "rationale": "Decision 25: the layout follows volume. The first 100 builder units run on a one-technician bench cell; the U cell bridges to about 4,500 a month and the balanced MadeCell line takes about 10,000. On any fixed eight-station line, split S8 first: it sits at 56 s against a 60 s takt and the Plus One+ checks would push it to 62 s", "tradeoffs": "a bench cell is cheap to set up but tops out at about 2,400 a month on one shift" }, "engine_notes": "The layout variants come from the N+1 factory engine (nplus1labs/factory 9bc6753), a discrete-event simulation that runs this OPD's routing with a ±30% spread on every target time. They are simulated from assumed values; uncalibrated; no unit built. The audio loopback, the RF check and wireless charging are outside the simulation. The other scores are expert estimates." } } }