Vehicle Routing Problem (VRP) - Example Hard Mixed-Integer Linear Programming MILP Problem
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- เผยแพร่เมื่อ 24 ส.ค. 2024
- This video is part of a lecture series available at / decisionmaking101
This video shows an example instance of the Vehicle Routing Problem (VRP) and how difficult it is to solve using a Mixed-Integer Linear Programming (MILP) model. The Excel file used in this video is available at bit.ly/2lYEjVS.
OpenSolver can be downloaded from: opensolver.org
My greatest admiration and respect professor for such amasing contribution. Thank you so much.
You are a life saver sir. Thank you, and keep up with the good work!
THANK YOU VERY MUCH I PASSED THE ASIGNATURE BECAUSE OF YOU
Hi, may I ask how would he model be if we wanted to make pickups and deliveries instead of fulfilling every delivery from a main warehouse? Thank you so much in advance!
How can I insert multiple vehicles with different capacities?
Are the constraints shown at the minute 4:48 the only ones which needs to be considered? How does the model ensure that the outflow from Node 1 should be at least equal to the sum of demand of the all other nodes?
how does your model ensure it sill start at node 1 and end with node 1?...OpenSolver is written by my supervisor. thanks for using
it doesnt, I have coded his mathematical model using gurobi and I got stuck with this problem, no constraint forces the vehicles to exit or return to the depot
How if it has 2 depots and there is demand that excess the truck capacity?
Thank you, sir, the video was very enlightening. Allow me to ask further. Have you ever discussed or solved problems related to airline network planning or airline base selection using Excel Solver like this? And then, how do you create an area plot from the decision variable matrix that you have made? Best Regards
excellent !
Can you explain the constraint pls
It was very useful and helpful so thank you. Is there any chance you can share the name of the article or paper which includes this mathematical model, pls
have you found the name of the article?
What are the units of distance between 2 points?
Do you have any idea how to formulate the model when we have more than 1 type of vehicle with different capacity? I think this might help. Thank you
Did you create the model for 2 vehicles?
Thanks for the video. can I have the excel worksheet for further understanding?
hey, please show how to make the graph from scratch
What heuristic did you use to solve for 30 customers?
Thank you very much!
can u show how to do it with lagragian relaxation
Thk u
Sir, how could we integreate the option of Multiple Trips per Vehicle ?
First of all, thanks for the very intersting video and explanations. I've checked the model and do not understand how can we avoid sub-routes and ensure that each routes goes through the 1 site?
One additionnal uestion: from what i've understood from th emodel the capacity imit is only from one site to another one and note cumulating the fgull quantity transpoted during the whole route. Is that right?
You need to create a subtour-elimination constraint. Check the DFJ or MZT formulations. Needless to say, you will need some heuristic approach if you want to solve to optimality when having more than 13-15 customers.
@@yasserbenazzouz No, the capacity is for the entire route of each vehicle. So it's a cumulative process from customer to customer.
Is it Possible to add the link for the Open source solver? That would be helpful Thanks
How one solve it using VBA?
I need help with my assignment (VRP TSP problem) can you assist me? Im willing to pay
I might have missed something, but how does truck go from to 1 to 10 (carrying 70+) and than from 10 to 4 (again carrying 70+) if total capacity of truck is 90? Shouldn't the truck return from 10 to 1 to resupply before heading to 4?
78-5 =73. Custemer_10 needs 5 items. And then customer 4 needs 5 items again. This pattern continous in this logic.
There way the problem is formulated is condiering capacity of that it's transporting from one location to the next on - as if it is picking the quantity for site 4 from site 10.
Divide the areas
Sir, thank you for sharing this model and the excel file. I have a question, if a maximum of 20 trucks may be used and split deliveries are allowed for certain customers, how may those constraints be formulated in OpenSolver in Excel? Thank you very much for your time.
For split deliveries, we would need to replace the first two constraints in the mathematical model by \sum_{j=1}^n x_{ij} = \sum{j=1}^n x_{ji} for all i=2..n (number of incoming trucks = number of outgoing trucks for each customer). To limit the number of trucks to 20, we would need \sum_{j=2}^n x_{1j} = 20.
Will it be possible to share the excel file with me too? It would be super helpful for me to understand the same. Let me know if you can help me.
Sir can you please help us understand the what the constraint E$79:AI$79
Excel constraints E$79:AI$79
@@DecisionMaking101 : Will it be possible to email worksheet being referred to here in the video? It would be super helpful.
@@DecisionMaking101 : Will it be possible to share the excel sheet which you used to demonstrate?
I was about to downvote you....until I saw that you uploaded your excel file for eveyone to see. Now I upvoted you.
this is dope
Hi, thnks for your wonderfull video. Is it possible to transform this problem design to VRF with time window.
can i asking u
@@rosebiba9847 I solved it with three sub-index (ijk). It may be difficult to solve VRP with time windows in this form showed in this video.
@@ademakgul6768 can you explain it to me, how did you do it?
@@manuelrodrigues4715 www.udemy.com/course/vehicle-routing-problem-with-spreadsheet/learn/lecture/22306076#content
I can send you a free coupon if you want.
@@ademakgul6768 yes please
4:50
Sum 2) j = 2, ..., n
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