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Hello. Recently I am trying to solve a problem using VRP extension about the delivery and pickup of railway containers transported by trucks between railway terminals (Depots) and the owners of the goods (Orders), in which I need to find a way to tell VRP that goods of certain orders should come from a certain depot and goods of certain orders should be delivered to another depot. In ArcGIS community I found this post in which you suggested using Route Specialties to achieve this but in that problem trucks (Routes) were assigned to a depot in advance, which means the end depot of all the trucks are fixed. So I use Order Pairs, which is another way you suggest if you want to keep the trucks free to get to any depots. Here is the way I use: Create an order at the location of the depot as a dummy depot point to be paired with the orders. Since one dummy depot can only be paired with one order point, I created dummy depot points for each order that need to be paired. For those delivery order points, the first order should be the dummy depot and the second order should be the order point. For those pickup order points, the first order should be the order point and the second order should be the dummy depot point. And to make the dummy depot points possible to be paired with, I gave them pickup and delivery quantities opposite to the order points the are to be paired with. Eg. Order1(Delivery)[Delivery=1, Pickup=0] → Depot1(Delivery)1[Delivery=0, Pickup=1] Order3(Pickup)[Delivery=0, Pickup=1] → Depot1(Pickup)1[Delivery=1, Pickup=0] By importing this table of order pairs, I run the VRP and got my results. Here are what I’d like to know: Creating dummy point for each order one by one could be a lot of work and seems a little bit clumsy. Is there any better way to assign orders to a depot without setting the end depot for the trucks in advance or to simplify the way of creating dummy points? In this way, there exists the possibility that dummy depot point being seen as an order and the sequence will be messed up. Are there any chances that other dummy points being put between a pair of first order and second order? Like: Depot1(Delivery)1 → Depot1(Pickup)1 → Order1(Delivery) → Order3(Pickup) when it should be: Depot1(Delivery)1 → Order1(Delivery) → Order3(Pickup) → Depot1(Pickup)1 If possible, could you give me some advice on how to prevent this kind of problem from happening? Thank you in advance for your kind help.
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11162021
09:23 PM

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Thank you for your kindness. Can I ask you some more questions? I got the output about total distance and time from four solves. In Pattern1 and Pattern2, total travel time is 329.109977 and total distance is 269818.52764. In Pattern 3 and Pattern4, total travel time is 328.119617 and total distance is 266143.493321. Pattern3 and 4 are shorter than Pattern1 and 2 in both total travel time and total distance. So, it contradicts that the total distance traveled is shorter for patterns 3 and 4 and that the shorter distance cost offsets the slightly longer travel time. Why? In addition, I want to understand when the algorithm converges. Could you tell me when the algorithm reaches convergence in VRP?
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11102021
05:57 PM

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Hello, I am a student trying to do a Vehicle Routing Problem with ArcGIS Pro Network Analyst. For the first, I tried some simple problems and got answers. However, I have some troubles. This is the 4 patterns I set up. Pattern1：Fixed Cost=0, Cost Per Unit Time=1, Cost Per Unit Distance=0 Pattern2：Fixed Cost=1, Cost Per Unit Time=1, Cost Per Unit Distance=0 Pattern3：Fixed Cost=0, Cost Per Unit Time=1, Cost Per Unit Distance=1 Pattern4：Fixed Cost=1, Cost Per Unit Time=1, Cost Per Unit Distance=1 *Every pattern has one route(Capacity=160, no time window). *16 visit places and 1 depot are the same in every pattern. *Visit Places：Service time=0, Delivery_1=10, no time window *Depot：Service time=0 Then, I got the answers. In Pattern1 and Pattern2, total travel time is 329.109977. In Pattern and Pattern4, total travel time is 328.119617. Why is the answer of Pattern1 and Pattern2 longer than that of Pattern and Pattern4? Please help me.
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