Minimizing Back Tracking Costing Weight (CWBT)

The Minimize Back Tracking costing weight (CWBT) is configured in the Costing Weights tab of the Schedule Parameter and Violation Sets screen.

Before you begin

In the Costing Weights tab, click Main Menu > Scheduling > Schedule Parameter and Violation Sets.

About this task

Costing Weights tab of the Schedule Parameter and Violation Sets screen
To configure costing weights, set their value between 1 and 25, which is used as a decimal value (a factor of 25). Depending on the purpose of the costing weight, the values are multiplied by the score, to scale the backtracking calculation to be heavier or lighter, thereby respectively increasing or reducing the total cost of a trip. In this case, CWBT affects the backtracking score to minimize.

To calculate backtracking cost for a run:

Procedure

  1. The distance is measured using triangulation from the pick-up event (PU) to the intermediary event (A) to determine Origin Distance 1 (OD1).
  2. The distance is measured using triangulation from A to the drop-off event (DO) to determine Destination Distance 1 (DD1)
  3. The distance is measured using triangulation from PU to B to determine Origin Distance 2 (OD2).
  4. The distance is measured using triangulation from B to DO to determine Destination Distance 2 (DD2).
  5. Calculate the backtracking score from the origin location if OD2 is less than OD1. If it is, then subtract OD2 from OD1:

    if (OD2 < OD1), then (OD1-OD2)

  6. Calculate the backtracking score from the destination location if DD2 is less than DD1. If it is, then subtract DD2 from DD1:

    if (DD2 < DD1), then (DD1-DD2)

  7. Repeat steps 1 to 6 for each pair of consecutive events in between the pick-up and drop-off events for every trip on the run itinerary.
  8. Add all scores from steps 5 and 6 together for the total amount of backtracking for the run.
  9. Multiply the difference between the total backtracking cost from before and after the new trip was inserted into the itinerary by the Minimize Back Tracking costing weight (CWBT):

    BTcosttrip = (BTcostbefore - BTcostafter) x CWBT