Stem is the component of driving time between the freight terminal and the area served. Individual P&D runs set up in the Cost Information System contain average trip weight (or stop time) used to allocate the stem portion of driving time to a specific stop. CIS contains a routine to adjust the P&D trip data to reflect the impact of the shipment stop being costed. This feature, the Dynamic P&D Stem Allocation, recalculates the run data by replacing one of the average stops with the shipment stop; thus adjusting the run to better reflect the dynamic nature of P&D trips.
Shipments having a stop weight which is below the P&D run average will receive a greater share of driving cost; because the trip weight will be adjusted down to reflect the impact of the smaller stop. Shipments with a greater than average stop weight will absorb less driving cost, because the trip weight will be increased to reflect the impact of the large stop. Systems allocating stem minutes on a stop time basis will have a similar adjustment: the trip stop time will be adjusted up or down to reflect the impact of the shipment stop being costed.
Three examples based on weight allocation are as follows:
P&D run data:
Stem Minutes 120
Trip Weight 18000
Number of Stops 10
|
Example Shipments |
A |
B |
C |
|
Stop Weight |
400 |
1800 |
4000 |
|
Static Allocation: Stop Weight / Trip Weight Stem Minutes Allocution |
0.022 2.7 |
0.100 12 |
0.222 26.7 |
|
CIS Dynamic Allocation: Average Wt per Stop x Remaining 9 Stops + This Stop New Trip Weight Stop Weight / New Trip Weight Stem Minutes Allocation |
1800 16200 400 16600 0.024 2.9 |
1800 16200 1800 18000 0.100 12 |
1800 16200 4000 20200 0.198 23.8 |
When calculated, the new trip weight cannot exceed the company average load x 2.