{
  "calculation_record_id": "DER-FEAS-001",
  "dataset_version": "2026.07.22-v2",
  "verified_date": "2026-07-22",
  "publisher": "Memphis Dock Door Repair Research",
  "url": "https://memphisdockdoorrepair.com/research/loading-dock-dimensions/",
  "description": "Reference-envelope feasibility interval calculation: whether the NOVA 2013 preliminary truck bed-height envelope can be served at any single dock height using the NHS hydraulic leveler maximum symmetric range.",
  "formula_id": "fleet-feasibility-interval",
  "formula": "feasibleInterval = [max(hMax - A), min(hMin + B)] across all entered vehicle groups",
  "inputs": {
    "vehicle_groups": [
      {
        "source_record_id": "NOVA-TRUCK-001",
        "label": "NOVA 2013 preliminary reference envelope (all six vehicle categories combined)",
        "assumption": "Single group spanning the full outer envelope; replace with measured fleet data before final design",
        "h_min_in": 36,
        "h_min_source": "NOVA-TRUCK-001 minimum (Straight truck low end)",
        "h_max_in": 62,
        "h_max_source": "NOVA-TRUCK-001 maximum (Container truck high end)"
      }
    ],
    "equipment": {
      "source_record_id": "NOVA-NHS-001",
      "leveler_name": "NOVA NHS Hydraulic Dock Leveler (maximum symmetric range from manual)",
      "above_dock_range_A_in": 12,
      "below_dock_range_B_in": 12,
      "assumption": "Maximum published symmetric range used for vertical-only screen; service height may vary with design specifications"
    }
  },
  "calculation_steps": [
    {
      "step": 1,
      "description": "Compute vehicle lower bound: hMax - A",
      "expression": "62 - 12",
      "result_in": 50,
      "meaning": "Minimum dock height at which leveler can reach up to hMax = 62 in"
    },
    {
      "step": 2,
      "description": "Compute vehicle upper bound: hMin + B",
      "expression": "36 + 12",
      "result_in": 48,
      "meaning": "Maximum dock height at which leveler can reach down to hMin = 36 in"
    },
    {
      "step": 3,
      "description": "Evaluate feasibility: lowerBound <= upperBound?",
      "expression": "50 <= 48",
      "result": false,
      "conclusion": "No single dock height satisfies both constraints simultaneously"
    }
  ],
  "outputs": {
    "fleet_interval_lower_in": 50,
    "fleet_interval_upper_in": 48,
    "result_status": "No single height covers the full entered envelope",
    "result_language": "No feasible single-height interval",
    "gap_in": 2,
    "gap_description": "Lower bound (50 in) exceeds upper bound (48 in) by 2 in. This appears as the 2-in upper mismatch gap in the interval visualization."
  },
  "limitations": [
    "The NOVA-TRUCK-001 ranges are 2013 preliminary planning references, not current national fleet statistics.",
    "Vertical range coverage is a necessary but not sufficient condition for dock-leveler compatibility.",
    "The NOVA-NHS-001 range is the maximum symmetric range from that product's manual; service height may vary with design specifications.",
    "This calculation does not evaluate lip engagement, capacity, bumper projection, rear-frame geometry, trailer float, end loading, underclearance, gradeability, or restraints.",
    "This is a geometric screen, not a structural, safety, code-compliance, or professional-approval determination."
  ],
  "regression_test_expected": {
    "expression": "[62 - 12, 36 + 12] = [50, 48]",
    "expected_status": "No feasible single-height interval"
  }
}