{"abstract":"Parcels are bumped into a higher cubic tier because measurements round up to the next quarter inch.","category":"Shipping rate zone lookup","checks":8,"contract":"dims inches, each rounded down to the quarter inch; weight lb. Eligible for cubic pricing when weight <= 20 and the longest rounded side <= 18. Cubic feet = product/1728, tier = tenths of a cubic foot rounded up (minimum 1); tiers above 5 are not cubic. Return [\"CUBIC\", tier] or [\"WEIGHT\", lb rounded up, minimum 1].","evaluation_group":"w2-shipping-zone-cubic-tiers","failed_approach":"Rounding down to whole inches discards legitimate quarter inches.","family":"w2-shipping-zone-cubic-tiers-quarter-inch-rounding","id":"FA-95601","implementations":{"attempt":{"sha256":"1c83a68bf80a69b9772f7f3d73e748ab050a21c41bbff842612b3c3984196713","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(dims, weight):\n    q = [Fraction(math.floor(d)) for d in dims]\n    lb = max(1, math.ceil(weight))\n    if weight > 20 or max(q) > 18:\n        return ['WEIGHT', lb]\n    cf = q[0] * q[1] * q[2] / 1728\n    tenths = math.ceil(cf * 10)\n    if tenths > 5:\n        return ['WEIGHT', lb]\n    return ['CUBIC', max(1, tenths)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['quarter inch down', [[8.2, 8.2, 8.2], 2], ['CUBIC', 3]], ['generated mix 10', [[8, 6.3, 18.2], 7.3], ['WEIGHT', 8]], ['one cubic foot', [[12, 12, 12], 5], ['WEIGHT', 5]], ['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['weight 20', [[6, 6, 6], 20], ['CUBIC', 2]], ['tier over cap', [[10, 10, 10], 1], ['WEIGHT', 1]], ['small cube', [[6, 6, 6], 2], ['CUBIC', 2]], ['generated mix 5', [[18.2, 6.3, 6], 20], ['CUBIC', 4]]], [['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['generated mix 7', [[10, 17.9, 4.6], 7.3], ['CUBIC', 5]], ['side exactly 18', [[18, 10, 4], 3], ['CUBIC', 5]], ['weight over 20', [[6, 6, 6], 20.5], ['WEIGHT', 21]], ['tier half', [[12, 12, 3], 1], ['CUBIC', 3]], ['small cube', [[6, 6, 6], 2], ['CUBIC', 2]], ['generated mix 9', [[18, 12, 6.3], 0.5], ['WEIGHT', 1]], ['generated mix 17', [[6, 19, 18], 19.9], ['WEIGHT', 20]]], [['generated mix 4', [[3, 18.2, 4.6], 0.5], ['CUBIC', 2]], ['generated mix 72', [[10, 9.9, 9.9], 0.5], ['WEIGHT', 1]], ['weight over 20', [[6, 6, 6], 20.5], ['WEIGHT', 21]], ['tier half', [[12, 12, 3], 1], ['CUBIC', 3]], ['small cube', [[6, 6, 6], 2], ['CUBIC', 2]], ['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['generated mix 19', [[18, 18, 6.3], 7.3], ['WEIGHT', 8]], ['generated mix 27', [[10, 8.2, 8], 20.5], ['WEIGHT', 21]]], [['generated mix 5', [[18.2, 6.3, 6], 20], ['CUBIC', 4]], ['generated mix 10', [[8, 6.3, 18.2], 7.3], ['WEIGHT', 8]], ['one cubic foot', [[12, 12, 12], 5], ['WEIGHT', 5]], ['quarter inch down', [[8.2, 8.2, 8.2], 2], ['CUBIC', 3]], ['side exactly 18', [[18, 10, 4], 3], ['CUBIC', 5]], ['weight over 20', [[6, 6, 6], 20.5], ['WEIGHT', 21]], ['generated mix 31', [[18, 6, 17.9], 19.9], ['WEIGHT', 20]], ['generated mix 39', [[19, 9.9, 19], 19.9], ['WEIGHT', 20]]], [['generated mix 6', [[10, 18.2, 4.6], 7.3], ['CUBIC', 5]], ['generated mix 7', [[10, 17.9, 4.6], 7.3], ['CUBIC', 5]], ['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['weight 20', [[6, 6, 6], 20], ['CUBIC', 2]], ['tier over cap', [[10, 10, 10], 1], ['WEIGHT', 1]], ['one cubic foot', [[12, 12, 12], 5], ['WEIGHT', 5]], ['generated mix 42', [[18, 6.3, 9.9], 2], ['WEIGHT', 2]], ['generated mix 50', [[18, 3, 19], 19.9], ['WEIGHT', 20]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"d54ae9df5560da2646dadad23788d82ff5454d177419ade346cd9fd5e152ba59","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(dims, weight):\n    q = [Fraction(round(d * 4), 4) for d in dims]\n    lb = max(1, math.ceil(weight))\n    if weight > 20 or max(q) > 18:\n        return ['WEIGHT', lb]\n    cf = q[0] * q[1] * q[2] / 1728\n    tenths = math.ceil(cf * 10)\n    if tenths > 5:\n        return ['WEIGHT', lb]\n    return ['CUBIC', max(1, tenths)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['quarter inch down', [[8.2, 8.2, 8.2], 2], ['CUBIC', 3]], ['generated mix 10', [[8, 6.3, 18.2], 7.3], ['WEIGHT', 8]], ['one cubic foot', [[12, 12, 12], 5], ['WEIGHT', 5]], ['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['weight 20', [[6, 6, 6], 20], ['CUBIC', 2]], ['tier over cap', [[10, 10, 10], 1], ['WEIGHT', 1]], ['small cube', [[6, 6, 6], 2], ['CUBIC', 2]], ['generated mix 5', [[18.2, 6.3, 6], 20], ['CUBIC', 4]]], [['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['generated mix 7', [[10, 17.9, 4.6], 7.3], ['CUBIC', 5]], ['side exactly 18', [[18, 10, 4], 3], ['CUBIC', 5]], ['weight over 20', [[6, 6, 6], 20.5], ['WEIGHT', 21]], ['tier half', [[12, 12, 3], 1], ['CUBIC', 3]], ['small cube', [[6, 6, 6], 2], ['CUBIC', 2]], ['generated mix 9', [[18, 12, 6.3], 0.5], ['WEIGHT', 1]], ['generated mix 17', [[6, 19, 18], 19.9], ['WEIGHT', 20]]], [['generated mix 4', [[3, 18.2, 4.6], 0.5], ['CUBIC', 2]], ['generated mix 72', [[10, 9.9, 9.9], 0.5], ['WEIGHT', 1]], ['weight over 20', [[6, 6, 6], 20.5], ['WEIGHT', 21]], ['tier half', [[12, 12, 3], 1], ['CUBIC', 3]], ['small cube', [[6, 6, 6], 2], ['CUBIC', 2]], ['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['generated mix 19', [[18, 18, 6.3], 7.3], ['WEIGHT', 8]], ['generated mix 27', [[10, 8.2, 8], 20.5], ['WEIGHT', 21]]], [['generated mix 5', [[18.2, 6.3, 6], 20], ['CUBIC', 4]], ['generated mix 10', [[8, 6.3, 18.2], 7.3], ['WEIGHT', 8]], ['one cubic foot', [[12, 12, 12], 5], ['WEIGHT', 5]], ['quarter inch down', [[8.2, 8.2, 8.2], 2], ['CUBIC', 3]], ['side exactly 18', [[18, 10, 4], 3], ['CUBIC', 5]], ['weight over 20', [[6, 6, 6], 20.5], ['WEIGHT', 21]], ['generated mix 31', [[18, 6, 17.9], 19.9], ['WEIGHT', 20]], ['generated mix 39', [[19, 9.9, 19], 19.9], ['WEIGHT', 20]]], [['generated mix 6', [[10, 18.2, 4.6], 7.3], ['CUBIC', 5]], ['generated mix 7', [[10, 17.9, 4.6], 7.3], ['CUBIC', 5]], ['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['weight 20', [[6, 6, 6], 20], ['CUBIC', 2]], ['tier over cap', [[10, 10, 10], 1], ['WEIGHT', 1]], ['one cubic foot', [[12, 12, 12], 5], ['WEIGHT', 5]], ['generated mix 42', [[18, 6.3, 9.9], 2], ['WEIGHT', 2]], ['generated mix 50', [[18, 3, 19], 19.9], ['WEIGHT', 20]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"fixed":{"sha256":"7b3264ec0ed54fbd053b2f48cc9cf94979b043b43c68ad4a3954a5885df2f7c3","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(dims, weight):\n    q = [Fraction(math.floor(d * 4), 4) for d in dims]\n    lb = max(1, math.ceil(weight))\n    if weight > 20 or max(q) > 18:\n        return ['WEIGHT', lb]\n    cf = q[0] * q[1] * q[2] / 1728\n    tenths = math.ceil(cf * 10)\n    if tenths > 5:\n        return ['WEIGHT', lb]\n    return ['CUBIC', max(1, tenths)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['quarter inch down', [[8.2, 8.2, 8.2], 2], ['CUBIC', 3]], ['generated mix 10', [[8, 6.3, 18.2], 7.3], ['WEIGHT', 8]], ['one cubic foot', [[12, 12, 12], 5], ['WEIGHT', 5]], ['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['weight 20', [[6, 6, 6], 20], ['CUBIC', 2]], ['tier over cap', [[10, 10, 10], 1], ['WEIGHT', 1]], ['small cube', [[6, 6, 6], 2], ['CUBIC', 2]], ['generated mix 5', [[18.2, 6.3, 6], 20], ['CUBIC', 4]]], [['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['generated mix 7', [[10, 17.9, 4.6], 7.3], ['CUBIC', 5]], ['side exactly 18', [[18, 10, 4], 3], ['CUBIC', 5]], ['weight over 20', [[6, 6, 6], 20.5], ['WEIGHT', 21]], ['tier half', [[12, 12, 3], 1], ['CUBIC', 3]], ['small cube', [[6, 6, 6], 2], ['CUBIC', 2]], ['generated mix 9', [[18, 12, 6.3], 0.5], ['WEIGHT', 1]], ['generated mix 17', [[6, 19, 18], 19.9], ['WEIGHT', 20]]], [['generated mix 4', [[3, 18.2, 4.6], 0.5], ['CUBIC', 2]], ['generated mix 72', [[10, 9.9, 9.9], 0.5], ['WEIGHT', 1]], ['weight over 20', [[6, 6, 6], 20.5], ['WEIGHT', 21]], ['tier half', [[12, 12, 3], 1], ['CUBIC', 3]], ['small cube', [[6, 6, 6], 2], ['CUBIC', 2]], ['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['generated mix 19', [[18, 18, 6.3], 7.3], ['WEIGHT', 8]], ['generated mix 27', [[10, 8.2, 8], 20.5], ['WEIGHT', 21]]], [['generated mix 5', [[18.2, 6.3, 6], 20], ['CUBIC', 4]], ['generated mix 10', [[8, 6.3, 18.2], 7.3], ['WEIGHT', 8]], ['one cubic foot', [[12, 12, 12], 5], ['WEIGHT', 5]], ['quarter inch down', [[8.2, 8.2, 8.2], 2], ['CUBIC', 3]], ['side exactly 18', [[18, 10, 4], 3], ['CUBIC', 5]], ['weight over 20', [[6, 6, 6], 20.5], ['WEIGHT', 21]], ['generated mix 31', [[18, 6, 17.9], 19.9], ['WEIGHT', 20]], ['generated mix 39', [[19, 9.9, 19], 19.9], ['WEIGHT', 20]]], [['generated mix 6', [[10, 18.2, 4.6], 7.3], ['CUBIC', 5]], ['generated mix 7', [[10, 17.9, 4.6], 7.3], ['CUBIC', 5]], ['side rounds to 18', [[18.2, 10, 4], 3], ['CUBIC', 5]], ['weight 20', [[6, 6, 6], 20], ['CUBIC', 2]], ['tier over cap', [[10, 10, 10], 1], ['WEIGHT', 1]], ['one cubic foot', [[12, 12, 12], 5], ['WEIGHT', 5]], ['generated mix 42', [[18, 6.3, 9.9], 2], ['WEIGHT', 2]], ['generated mix 50', [[18, 3, 19], 19.9], ['WEIGHT', 20]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Stipulated tier sizes and eligibility. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-shipping-zone-cubic-tiers-quarter-inch-rounding","generated_at":"2026-09-29T14:52:15.164818+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Cubic pricing rates small dense parcels by volume tier instead of weight.","repair":"Round each dimension down to the quarter inch.","root_cause":"Dimensions are rounded to the nearest quarter inch instead of down.","sha256":"c6412850caa17aa5b75eaa05d4c63b234bd3645d2b9497beb9941c4469c03c31","title":"Cubic tiers: quarter inches rounded to nearest · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":42.793,"exit_code":1,"observations":[{"actual":["CUBIC",3],"check":"quarter inch down","expected":["CUBIC",3],"passed":true},{"actual":["CUBIC",5],"check":"generated mix 10","expected":["WEIGHT",8],"passed":false},{"actual":["WEIGHT",5],"check":"one cubic foot","expected":["WEIGHT",5],"passed":true},{"actual":["CUBIC",5],"check":"side rounds to 18","expected":["CUBIC",5],"passed":true},{"actual":["CUBIC",2],"check":"weight 20","expected":["CUBIC",2],"passed":true},{"actual":["WEIGHT",1],"check":"tier over cap","expected":["WEIGHT",1],"passed":true},{"actual":["CUBIC",2],"check":"small cube","expected":["CUBIC",2],"passed":true},{"actual":["CUBIC",4],"check":"generated mix 5","expected":["CUBIC",4],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"quarter inch down\", \"actual\": [\"CUBIC\", 3], \"expected\": [\"CUBIC\", 3], \"passed\": true}, {\"check\": \"generated mix 10\", \"actual\": [\"CUBIC\", 5], \"expected\": [\"WEIGHT\", 8], \"passed\": false}, {\"check\": \"one cubic foot\", \"actual\": [\"WEIGHT\", 5], \"expected\": [\"WEIGHT\", 5], \"passed\": true}, {\"check\": \"side rounds to 18\", \"actual\": [\"CUBIC\", 5], \"expected\": [\"CUBIC\", 5], \"passed\": true}, {\"check\": \"weight 20\", \"actual\": [\"CUBIC\", 2], \"expected\": [\"CUBIC\", 2], \"passed\": true}, {\"check\": \"tier over cap\", \"actual\": [\"WEIGHT\", 1], \"expected\": [\"WEIGHT\", 1], \"passed\": true}, {\"check\": \"small cube\", \"actual\": [\"CUBIC\", 2], \"expected\": [\"CUBIC\", 2], \"passed\": true}, {\"check\": \"generated mix 5\", \"actual\": [\"CUBIC\", 4], \"expected\": [\"CUBIC\", 4], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.617,"exit_code":1,"observations":[{"actual":["CUBIC",4],"check":"quarter inch down","expected":["CUBIC",3],"passed":false},{"actual":["WEIGHT",8],"check":"generated mix 10","expected":["WEIGHT",8],"passed":true},{"actual":["WEIGHT",5],"check":"one cubic foot","expected":["WEIGHT",5],"passed":true},{"actual":["WEIGHT",3],"check":"side rounds to 18","expected":["CUBIC",5],"passed":false},{"actual":["CUBIC",2],"check":"weight 20","expected":["CUBIC",2],"passed":true},{"actual":["WEIGHT",1],"check":"tier over cap","expected":["WEIGHT",1],"passed":true},{"actual":["CUBIC",2],"check":"small cube","expected":["CUBIC",2],"passed":true},{"actual":["WEIGHT",20],"check":"generated mix 5","expected":["CUBIC",4],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"quarter inch down\", \"actual\": [\"CUBIC\", 4], \"expected\": [\"CUBIC\", 3], \"passed\": false}, {\"check\": \"generated mix 10\", \"actual\": [\"WEIGHT\", 8], \"expected\": [\"WEIGHT\", 8], \"passed\": true}, {\"check\": \"one cubic foot\", \"actual\": [\"WEIGHT\", 5], \"expected\": [\"WEIGHT\", 5], \"passed\": true}, {\"check\": \"side rounds to 18\", \"actual\": [\"WEIGHT\", 3], \"expected\": [\"CUBIC\", 5], \"passed\": false}, {\"check\": \"weight 20\", \"actual\": [\"CUBIC\", 2], \"expected\": [\"CUBIC\", 2], \"passed\": true}, {\"check\": \"tier over cap\", \"actual\": [\"WEIGHT\", 1], \"expected\": [\"WEIGHT\", 1], \"passed\": true}, {\"check\": \"small cube\", \"actual\": [\"CUBIC\", 2], \"expected\": [\"CUBIC\", 2], \"passed\": true}, {\"check\": \"generated mix 5\", \"actual\": [\"WEIGHT\", 20], \"expected\": [\"CUBIC\", 4], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.576,"exit_code":0,"observations":[{"actual":["CUBIC",3],"check":"quarter inch down","expected":["CUBIC",3],"passed":true},{"actual":["WEIGHT",8],"check":"generated mix 10","expected":["WEIGHT",8],"passed":true},{"actual":["WEIGHT",5],"check":"one cubic foot","expected":["WEIGHT",5],"passed":true},{"actual":["CUBIC",5],"check":"side rounds to 18","expected":["CUBIC",5],"passed":true},{"actual":["CUBIC",2],"check":"weight 20","expected":["CUBIC",2],"passed":true},{"actual":["WEIGHT",1],"check":"tier over cap","expected":["WEIGHT",1],"passed":true},{"actual":["CUBIC",2],"check":"small cube","expected":["CUBIC",2],"passed":true},{"actual":["CUBIC",4],"check":"generated mix 5","expected":["CUBIC",4],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"quarter inch down\", \"actual\": [\"CUBIC\", 3], \"expected\": [\"CUBIC\", 3], \"passed\": true}, {\"check\": \"generated mix 10\", \"actual\": [\"WEIGHT\", 8], \"expected\": [\"WEIGHT\", 8], \"passed\": true}, {\"check\": \"one cubic foot\", \"actual\": [\"WEIGHT\", 5], \"expected\": [\"WEIGHT\", 5], \"passed\": true}, {\"check\": \"side rounds to 18\", \"actual\": [\"CUBIC\", 5], \"expected\": [\"CUBIC\", 5], \"passed\": true}, {\"check\": \"weight 20\", \"actual\": [\"CUBIC\", 2], \"expected\": [\"CUBIC\", 2], \"passed\": true}, {\"check\": \"tier over cap\", \"actual\": [\"WEIGHT\", 1], \"expected\": [\"WEIGHT\", 1], \"passed\": true}, {\"check\": \"small cube\", \"actual\": [\"CUBIC\", 2], \"expected\": [\"CUBIC\", 2], \"passed\": true}, {\"check\": \"generated mix 5\", \"actual\": [\"CUBIC\", 4], \"expected\": [\"CUBIC\", 4], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}