Banding

You have a continuous value like driver age or sum insured, but your rating structure needs age bands or value brackets. The Banding node turns a column of raw values into a column of bands, using rules you define. It also works with categorical values - grouping many fuel types into "Standard" vs "Green", for example.

Spreadsheet equivalent

This replaces nested IF statements in Excel (e.g. =IF(age<=25, "18-25", IF(age<=65, "26-65", "65+"))) or banding definitions in tools like Earnix or Radar.

When to use

• Converting continuous values (age, mileage, sum insured) into discrete bands for your rating tables.
• Grouping categorical values into broader categories.
• Preparing inputs for a Rating Step that expects banded values.

This node accepts a single input.

Config	Description
factors	Required. List of banding factors

Each factor has:

Field	Description
column	Required. Input column to band
outputColumn	Required. Name of the new banded column
banding	Required. "continuous", "categorical", or "breakpoints"
rules	Required. Rules defining each band. Continuous rules are a list; categorical and breakpoint sidecars use key/value maps
default	Value assigned to rows that don't match any rule

Rules are evaluated top to bottom. The first match wins.

Continuous rules define ranges using operator/value pairs. Each rule can use one or both conditions. Operators: <, <=, >, >=, =.

This example bands driver age into three groups:

{
  "factors": [{
    "banding": "continuous",
    "column": "driver_age",
    "outputColumn": "age_band",
    "rules": [
      { "op1": ">=", "val1": "18", "op2": "<=", "val2": "25", "assignment": "18-25" },
      { "op1": ">",  "val1": "25", "op2": "<=", "val2": "65", "assignment": "26-65" },
      { "op1": ">",  "val1": "65", "op2": "",   "val2": "",   "assignment": "65+" }
    ],
    "default": "Unknown"
  }]
}

Categorical rules map exact values to groups. In the JSON sidecar, the source value is the key and the assigned group is the value:

{
  "factors": [{
    "banding": "categorical",
    "column": "fuel_type",
    "outputColumn": "fuel_band",
    "rules": {
      "Petrol": "Standard",
      "Diesel": "Standard",
      "Electric": "Green"
    },
    "default": "Other"
  }]
}

Breakpoint rules are a concise way to define ordered numeric bands. The boundary is the key and the assigned band is the value. Use an empty-string key for the open-ended final band:

{
  "factors": [{
    "banding": "breakpoints",
    "column": "driver_age",
    "outputColumn": "age_band",
    "rules": {
      "25": "18-25",
      "65": "26-65",
      "": "65+"
    },
    "default": "Unknown"
  }]
}

Before and after:

BEFORE                              AFTER
| driver_age | fuel_type |          | driver_age | fuel_type | age_band | fuel_band |
|------------|-----------|          |------------|-----------|----------|-----------|
| 22         | Petrol    |    →     | 22         | Petrol    | 18-25    | Standard  |
| 45         | Electric  |          | 45         | Electric  | 26-65    | Green     |
| 71         | Diesel    |          | 71         | Diesel    | 65+      | Standard  |

Watch for gaps

Rows that don't match any rule get the default value. Make sure your ranges don't have gaps unless you intentionally want unmatched rows to fall through to the default.