Additional handling
- Louis D'hondt
- Maura Lemaire
- Bert Claes
Feature use case
This feature discourages PTV OptiFlow from creating routes in VRP backhaul that violate the LIFO (last in, first out) principle.
Consider a VRP backhaul planning containing following route:
The driver will start this route with the deliveries already in his vehicle. First he will load his pickup, at which point all orders are present in the vehicle. At the following order he wants to unload his first delivery, but this is made more difficult by the pickup already being present: this pickup will occupy some space in the vehicle and possibly block the vehicle entrance for the driver. Hence the driver will need to spend some effort rearranging the contents of the vehicle before he can easily unload this delivery and the subsequent one. Rearranging the contents of a vehicle will require some extra free space reorganize the contents of the vehicle. This is undesirable if the vehicle does not have this free space.
The handling feature addresses such scenarios. When using this feature PTV OptiFlow will take into account for which routes this extra effort is too high, and steer away from such routes.
Feature description
When a pickup is followed by a delivery in a VRP backhaul route, the LIFO principle is violated. This requires extra effort to reorganise the vehicle. We will estimate the capacity required for this reorganisation, i.e. the handling capacity, and penalise the exceeded amount if this capacity exceeds the maximum capacity of the vehicle.
The handling capacity and the corresponding penalty are computed based on the following parameters.
Settings tab → advanced settings
Capacity: the capacity used to calculate the handling capacity
Additional handling percentage: the percentage of additional capacity required per order when reorganising these types of orders in the vehicle
Excess handling penalty: penalty per unit that the handling capacity exceeds the vehicle capacity
Order
Additional handling percentage: the percentage of additional capacity required when reorganising this specific order on a vehicle, this overwrites the global value
These parameters allow PTV OptiFlow to compute the additional handling capacity for each order. This is the capacity of the order, with respect to chosen capacity type, multiplied by the additional handling percentage.
Example
Suppose that the handling capacity is calculated with respect to the capacity “Volume”. If an order has a volume of 3 m3 and an additional handling percentage of 150%, its additional handling capacity is 3 m3 x 150% = 4.5 m3. This means that an additional 4.5 m3 of empty space is required in the vehicle when reorganisation is needed with this order present in the vehicle.
OptiFlow computes the handling capacity every time the LIFO principle is violated. This happens when a pickup is followed by a delivery in a VRP backhaul route. The required handling capacity is the sum of the capacity of the pickups and deliveries present when the LIFO principle is violated, and the additional capacity required to reorganise the vehicle. The latter is the additional handling capacity of all pickups or all deliveries, whichever is the least. When reorganising the orders present in a vehicle, we either need to pass all deliveries with all pickups or we need to pass all pickups with all deliveries. Therefore we only take into account the extra handling capacity of either the pickups or deliveries, whichever requires the least amount of capacity.
If the handling capacity exceeds the capacity of the vehicle, this results in a penalty equal to the exceeded amount multiplied by the excess handling penalty.
Examples
Capacity: volume
Additional handling percentage: 120
Excess handling penalty: 1.3
vehicle capacity: 26m3.
pickup capacity: 15m3
delivery 1 capacity: 6m3
delivery 2 capacity: 4m3
This route violates the LIFO principle, hence the extra handling will be calculated. Since no order has a specific additional handling percentage, the value from Settings is used: 120%.
Pickup has an extra order handling of 120 * 15 / 100 m3= 18m3
Delivery 1 has an extra order handling of 120 * 6 / 100m3= 9m3
Delivery 2 has an extra order handling of 120 * 4 / 100 m3= 6m3
The total pickup additional handling capacity is 18m3, the total delivery additional handling capacity is 15m3. The actual additional handling capacity is the minimum of these two: 15m3. The total handling capacity is the sum of this value (15m3), the sum of present pickups (15m3) and the sum of present deliveries (10m3): 40m3. This exceeds the capacity of the vehicle by 14m3, leading to a penalty of 1.3 * 14 = 18.2.