Back Load Allowance

Hello All,

I have requirement relating to back load allowance.

What is back load allowance?

It is a allowance that driver receives when he come back to its home location with a Load and that to in stipulated time period, if he comes empty the driver or late he is not entitled to receive the same.

Scenario:

Say for an example, we have currently 3 locations X, Y and Z.

Scenario 1st:
Driver Home Location is X.
From X to Y takes 15 hrs. Back Load Allowance Amount = 20 SAR
From Y to X takes 15 hrs. Back Load Allowance Amount = 20 SAR

Now the driver is going from X to Y with a load, and completes the journey say in 15 hrs and come back with a new shipment from Y to X and completes the journey in 15 hrs. So he will be entitled to receive 40 SAR as Back load allowance when is comes back to X location.

Scenario 2nd:
Driver Home Location is X.
From X to Y takes 15 hrs. Back Load Allowance Amount = 20 SAR
From Y to Z takes 20 hrs. Back Load Allowance Amount = 30 SAR
From Z to X takes 10 hrs. Back Load Allowance Amount = 40 SAR

Now the driver is going from X to Y with a load, and completes the journey say in 15 hrs and now with a new shipment goes from Y to Z and completes the journey in 20 hrs and returns back with new shipment from Z to X and complete the journey in 10 hrs. So he will be entitled to receive 90 SAR as Back load allowance when is comes back to X location.

The cycle will go on and the amount will be added till driver does not come back to its home location.

I am not able to get how can we do this. :(

Regards,
Pratik