About Calculating Trip Costs

All scheduling decisions are performed based on the “cost” of a trip.

To decide which trip to flag and remove from its current location on the run itinerary, the system calculates the “cost” of each trip in every possible time slot available on every run.

The system uses the following formula to calculate the cost of a trip for each costing weight: (NewValue - OldValue) x Costing Weight = Trip Cost.

These costs are added together to calculate a total score for a trip. Lower scores are more desirable than higher scores.

For example, consider a scenario with two runs, Run A and Run B. Each run has a pick-up and drop-off trip: Trip 1 is scheduled on Run A, and Trip 2 is scheduled on Run B.

Table 1. Runs A and B before Trip 3 is inserted
Run A	Distance	Run B	Distance
Garage Pullout	--	Garage Pullout	--
Pickup Trip 1	5 km	Pickup Trip 2	10 km
Drop-off Trip 1	5 km	Drop-off Trip 2	10 km
Garage Pull-in	10 km	Garage Pull-in	10 km
Total Distance	20 km	Total Distance	30 km

The Schedule Parameter set is configured to use the Minimize Distance costing weight (CWD), whose goal is to minimize the distance for a trip on a given set of runs. Using the BTL, a run needs to be selected on which to insert a third pick-up and drop-off trip for Trip 3.

Table 2. Runs A and B after Trip 3 is inserted
Run A	Distance	Run B	Distance
Garage Pullout	--	Garage Pullout	--
Pickup Trip 1	5 km	Pickup Trip 2	10 km
Pickup Trip 3	10 km	Pickup Trip 2	10 km
Drop-off Trip 3	10 km	Drop-off Trip 3	2 km
Drop-off Trip 1	10 km	Drop-off Trip 3	10 km
Garage Pull-in	10 km	Garage Pull-in	3 km
New Distance	45 km	New Distance	35 km

The calculation for Run A is as follows:

(NewValue - OldValue) x Costing Weight = CWD Score
(45 - 20) x 10 = 256

The calculation for Run B is as follows:

(NewValue - OldValue) x Costing Weight = CWD Score
(35 - 30) x 10 = 50

These calculations show that Run B has a lower costing weight; therefore, Trip 3 is inserted on to Run B.