Extrapolation with Billing Factor 
The expected meter reading is calculated from the expected consumption with the help of special parameters (register factor, billing factor, dimension conversion table). The following example shows the significance of the billing factor.
On installation of the device, a period consumption value of 4000 kWh/year is entered for the register.
The minimum portion of weighting in percent is 30%.
The sum of the weighting units for one year is 1000.
With a weighting portion of 40%, period Y to I is representative. This means that extrapolation is based on meter reading results rather than on period consumption.
Determination of meter reading difference Y to I:
800 kWh – 0 kWh = 800 kWh
Determination of consumption to Y by multiplying the meter reading difference with the register factor:
800 kWh * 2 = 1600 kWh
Determination of consumption to Y by multiplying the meter reading difference with the conversion factor (gas):
1,600 kWh * 10 = 16,000 kWh
Determination of consumption to Y by multiplying with the billing factor:
16,000 kWh * 1.5 = 24,000 kWh
Determination of consumption per weighting unit:
24,000 kWh: 400 = 60 kWh
Extrapolation of fictitious consumption for period Y to P:
60 kWh * 600 = 36,000 kWh
Determination of the actual, new consumption for period P based on the quotient of the new and the old billing factor
(36,000 kWh : 1.5) * 2 kWh * 2 = 48,000 kWh
Determination of the meter reading difference for period Y to P by dividing the consumption value by the billing factor:
48,000 kWh : 2 = 24,000 kWh
Determination of the meter reading difference for period Y to P by dividing the consumption value by the conversion factor (gas):
24,000 kWh : 12 = 2,000 kWh
Determination of the meter reading difference for period Y to P by dividing the consumption value by the register factor:
2,000 kWh : 10 = 200 kWh
Determination of the expected meter reading to P by adding the meter reading difference to meter reading Y:
800 kWh + 200 kWh = 1,000 kWh
The expected meter reading at time P is 1,000 kWh .
The billing factor effects the expected consumption. As a result of weighting distribution, the consumption value from the base period is transformed to the extrapolation period and given the value of the new billing factor. The new expected consumption value is then divided by the factors that are valid on the extrapolation date (register factor, conversion factors) in order to determine the expected meter reading values.
During extrapolation, the conversion factors are determined on a key date (in the same way as the register factors). This means that the conversion factors are defined for the extrapolation date (this is usually the planned meter reading date) in order to transform the expected consumption value into an expected meter reading value. In billing, the entire billing period is analyzed for changed conversion factors and is then valuated and prorated accordingly. This is not possible for extrapolation as the data is not yet available when extrapolation takes place.
For more information on valuating the billing period with gas factors, see the documentation for contract billing in the implementation guide (IMG) under Special Functions -> Gas Billing .