Rating is performed by taking the details about a risk type (fields, items, rate tables, and calculations) and details about a quote (risks, field answers, chosen items) and combining them to determine each item’s premium, limits, and deductible.
Calculations are single-line statements that return a numeric result.
baseRate * rateFactorTable * seniorDiscount
This calculation says to take the
baseRate and multiply it by the
rateFactorTable and the
Each field, item, rate table, and calculation has a reference name. Calculations use this reference name to refer to the fields, items, rate tables, and calculations. This allows information about these entities to change (like updating a label or default value) without affecting rating logic.
Valid reference names
A reference name must be a valid Python identifier. This means a reference name can only start with a letter or underscore and can only contain letters, numbers, and underscores.
The following are valid reference names:
The following are invalid reference names:
$value(contains a dollar sign)
1stdriver(starts with a number)
Reserved reference names
Some reference names are already reserved by BriteLines. These reference names are unavailable to be used by any field, rate table, calculation, or item.
The following reference names are reserved by BriteLines along with other Python built-ins:
The following arithmetic operations can be performed on references that return numbers (fields of type number, rate tables, and calculations).
+ character is used to add numbers together.
baseRateTable + numberField + otherCalculation
- character is used to subtract one number from another number.
baseRateTable - numberField
* character is used to multiply numbers together.
baseRateTable * rateTableFactor
/ character is used to divide one number by another number.
baseRateTable / 2
Comparison operations compare values and return either true or false according to the condition.
True if the left operand is greater than the right.
numOfDrivers > numOfVehicles
True if the left operand is less than the right.
numOfDrivers < numOfVehicles
True if both operands are equal.
numOfDrivers == numOfVehicles
Not equal to
True if operands aren’t equal.
numOfDrivers != numOfVehicles
Greater than or equal to
True if the left operand is greater than or equal to the right.
numOfDrivers >= numOfVehicles
Less than or equal to
True if the left operand is less than or equal to the right.
numOfDrivers <= numOfVehicles
Scopes determine which references are available for calculation. Shared calculations and item calculations have different scopes.
Shared calculations have a scope that can reference all fields, rate tables, and other shared calculations. They can’t reference specific item calculations.
Item calculations have a scope that can reference all fields, rate tables, shared calculations, and the other calculations for that item.
Because of these rules, shared calculation reference names must be unique across all fields, items, rate tables, and calculations. Item calculations reference names, however, only need to be unique across fields, items, rate tables, shared calculations, and the current item’s calculations.
comprehensive could both have calculations called
baseRate, because the names wouldn’t clash. You couldn’t, however, have a shared calculation called
baseRate, because when rating the
bodilyInjury item, the rating engine wouldn’t know if it should use the value from the item’s
baseRate calculation or the risk type’s
baseRate shared calculation.
Circular reference errors
Calculations must not reference each other.
You couldn’t have the two calculations below. They would result in a circular reference error because
baseRate refers to
rateCalc refers to
baseRate. The rating engine wouldn’t have any way of determining the value for either one.
rateCalc * seniorDiscount
baseRate * otherFactor
Calculations have the following types:
Variable calculations simply perform the calculation and store it in the reference name. The result can then be used by other calculations. All shared calculations are variable calculations.
Premium, limit, and deductible calculations result in the item’s premium, limit, and deductible respectively.
The date on which the policy was first created.
If the policy inception date is 2014-01-01 and the rating date is 2017-01-01, then the above calculation will resolve to 3.
The effective date of the current transaction.
The effective date of the current term.
True if the current transaction type is New Business; otherwise, it will return
2 if bc.isTransactionNewBusiness else 4
If the transaction type is New Business, then the above calculation will return 2; otherwise, it will return 4.
True if the current transaction type is Renewal; otherwise, it will return
2 if bc.isTransactionRenewal else 4
If the transaction type is Renewal, then the above calculation will return 2; otherwise, it will return 4.
True if the current transaction type is Endorsement; otherwise, it will return
2 if bc.isTransactionEndorsement else 4
If the transaction type is Endorsement, then the above calculation will return 2; otherwise, it will return 4.
True if the current transaction type is Cancellation; otherwise, it will return
2 if bc.isTransactionCancellation else 4
If the transaction type is Cancellation, then the above calculation will return 2; otherwise, it will return 4.
True if the current transaction type is Rewrite; otherwise, it will return
2 if bc.isTransactionRewrite else 4
If the transaction type is Rewrite, then the above calculation will return 2; otherwise, it will return 4.
The rating engine provides several functions that you can use in your calculations.
This function marks data fields, rate tables, and items as optional. If a rate table is marked as optional, then BriteLines will determine which fields the rate table uses as sources and mark them as optional.
bc.optional(), wrap the data field, rate table, or item reference names in the function.
bc.optional with Rate Tables
bc.optional, all of the data fields that
secondaryDriverRateTable points to will be optional during quoting.
secondaryDriverRateTable has no default value set or you want to override the default value, then you can pass a default value to the
Note: The default value must be a number.
bc.min(primaryDriverRateTable, bc.optional(secondaryDriverRateTable, default=1))
bc.optional with Items
mandatoryItem.premium.term.value + bc.optional(optionalItem.premium.term.value, default=0)
In this example, we add a mandatory item’s premium to an optional item’s premium.
- If the mandatory item’s premium is 50 and the optional item exists on the policy and has a premium of 50, then this calculation will return 100.
- If the mandatory item’s premium is 50 and the optional item hasn’t been enabled for the policy, then this calculation will return 50.
- If the mandatory item’s premium is 50 and the optional item exists on the policy but can’t be resolved yet, then this calculation will return 50.
Optional fields in quoting
During quoting, a field will only be considered optional if:
- All calculations that refer directly to the field are wrapped in
- All rate tables that refer to the field are wrapped in
This means a field can be optional or required depending on the items selected for a risk.
- If a quote has Item 1 enabled, then all Item 1 calculations mark the
additionalDriverfield as optional. It is optional on the quote.
- If Item 2 is enabled on the quote and it has calculations that refer to
additionalDriver, which aren’t wrapped in
bc.optional(), then Additional Driver becomes a required field (because it’s not filled out, then Item 2 couldn’t rate).
Returns the age of something in years from a given date or number.
This allows us to always collect the date of origin and find its age dynamically. When we collect birthday, year built, and year purchased,
bc.age() will always use the quote’s rating date to find the age based on these dates.
If the following are true:
- You collect
dateOfBirthas a date input
- The user chooses “01/31/1992”
- The rating date year is 2017
bc.age(dateOfBirth) will return 25.
This function isn’t simply the difference in years; it also accounts for aging in the current year. So if the rating date is “12/13/2017” and the user types “12/15/2000”, then the value is not 17, but 16 because the 15th hasn’t yet passed.
Users can also pass in numbers, in which case
bc.age() assumes the number is a year. For instance, a calculation of
bc.age(2010) will return 8 if the current year is 2018. This is useful for calculating the age of vehicles:
bc.age() will always return the difference between the rating date and the value passed into the function. This means
bc.age() may return a negative number for future dates and years. To ensure that no values lower than 0 are returned, change your calculation to:
Returns different results based on whether the condition is true or false.
bc.condition(hasAntiLockBrakes, 0.95, 1.0)
If the user has selected
Yes for the
hasAntiLockBrakes boolean field, this calculation would return 0.95. If the user hasn’t selected
Yes, then it would return 1.0.
Returns different results based on whether the risk has a specific item selected.
bc.if_item('comprehensive', 0.95, 1.0)
This calculation would return 0.95 if the comprehensive coverage is present on the quote. If the coverage isn’t present, then the calculation would return 1.0.
Rounds values based on
bc.round(some_number, round_to=bc.NEAREST_HUNDRED, round_method=bc.ROUND_UP)
bc.round also works with an alternative syntax:
This is a simplified version that would round
some_number to the second decimal place.
round_tooptions default to
TWO_DECIMALS(the nearest penny).
round_methodoptions default to
Returns the maximum value from all values passed to it. If
primaryDriverRateTable resolves to 800.0 and
secondaryDriverRateTable resolves to 400.0, then the following function would return 800.0.
Returns the minimum value from all values passed to it. If
primaryDriverRateTable resolves to 800.0 and
secondaryDriverRateTable resolves to 400.0, then the following function would return 400.0.
<itemName>.limits.<limitName> to access an item’s limits.
Pro-Rata premium calculation
When a premium-bearing change is made to a policy mid-term, affected items must prorate the premium against the term. When a policy is canceled mid-term, items must be prorated based upon the cancellation effective date.
The pro-rata premium can be determined against different transaction types with different term lengths and granularity.
Pro-rata premium is calculated and stored per item. The total policy pro-rata premium and policy term premium are also calculated and stored. The total pro-rata premium and the policy term premium, as well as each individual item pro-rata premium and policy term premium, are displayed in Rate Preview.
The pro-rata premium calculation currently assumes a one-year policy term with “day” granularity, meaning that the premium is calculated to the day.
Total pro-rata premium is calculated as the sum of all individual item pro-rata premiums.
Pro-rata premium per item is calculated as follows:
((units * (calculated rate - prior rate))/granularity) + prior pro-Rata premium
- Term: 1 year
- Effective date: 1/1/2017
- Granularity: day (365 units for 1/1/2017 – 1/1/2018)
Policy Inception – 1/1/2017
- Full term amount: $365
- Units = days(1/1/2018 – 1/1/2017) = 365
- Calculated rate = 365
- Prior rate = 0
- Prior pro-rata premium = 0
- Pro-rata premium = ((365 * (365 – 0)) / 365) + 0 = $365
Endorsement – 5/3/2017
- Full term amount: $730
- Units = days(1/1/2018 – 5/3/2017) = 243
- Calculated rate = 730
- Prior rate = 365
- Prior pro-rata premium = 365
- Pro-rata premium = ((243 * (730 – 365)) / 365) + 365 = $608
Endorsement – 9/2/2017
- Full term amount: $1095
- Units = days(1/1/2018 – 9/2/2017) = 121
- Calculated rate = 1095
- Prior rate = 730
- Prior pro-rata premium = 608
- Pro-rata premium = ((243 * (730 – 365)) / 365) + 365 = $729