Hello there,
is there anyone in possession of a running Gams-code for the classical CVRP and would like to share it?
Thank you all in advance. I hope i dont disregard any Rules of this forum with this request.
with best regards
Capacitated Vehicle Routing Problem
Re: Capacitated Vehicle Routing Problem
Hi,
First of all I am new within the GAMS forum. As part of my master's thesis I am currently creating a GAMS model and first tried to model the CVRP.
My model is based on the mathematical model formulation according to Fisher and Jaikumar (1981), where I would like to add a subtour elimination constraint, for example according to Miller, Tucker and Zemlin.
Without the subtour elimination constraint my model runs, but subtours are created of course.
Therefore I took a deeper look to tsp2.gms and tsp5.gms models I found in GAMS library.
Unfortunately, until now I had no success to include the subtour elimination constraint and time for my master thesis is of course running If you still need the model, feel free to have a look at my version attached.
Maybe someone has an idea of how to adjust the model so that a subtour constraint is working?
Many thanks in advance!
Best regards
Liza
First of all I am new within the GAMS forum. As part of my master's thesis I am currently creating a GAMS model and first tried to model the CVRP.
My model is based on the mathematical model formulation according to Fisher and Jaikumar (1981), where I would like to add a subtour elimination constraint, for example according to Miller, Tucker and Zemlin.
Without the subtour elimination constraint my model runs, but subtours are created of course.
Therefore I took a deeper look to tsp2.gms and tsp5.gms models I found in GAMS library.
Unfortunately, until now I had no success to include the subtour elimination constraint and time for my master thesis is of course running If you still need the model, feel free to have a look at my version attached.
Maybe someone has an idea of how to adjust the model so that a subtour constraint is working?
Many thanks in advance!
Best regards
Liza
Re: Capacitated Vehicle Routing Problem
Hi again,
In the meantime I have a CVRP model including a subtour elimination which might work: Nevertheless, when running the model I get an error message: Can someone help me?
The questions are:
In addition, I also have a licence of GAMS/GUROBI link as well as GUROBI 9 license, but until no I have no idea how to activate that.
Many thanks in advance for your help.
Best regards
Liza
In the meantime I have a CVRP model including a subtour elimination which might work: Nevertheless, when running the model I get an error message: Can someone help me?
The questions are:
- Is the model correct, so that it would work if the license would allow to run the model?
- Do I need a special license to include a full solver?
In addition, I also have a licence of GAMS/GUROBI link as well as GUROBI 9 license, but until no I have no idea how to activate that.
Many thanks in advance for your help.
Best regards
Liza
Re: Capacitated Vehicle Routing Problem
Hi again,
Regarding my previous questions, I just wanted to let you know that I now have an appropriate model formulation of the CVRP with subtour elimination that works and provides an optimal result.
The above questions are therefore no longer relevant for me personally.
If anyone is interested in the model formulation, please feel free to get back to me.
Best regards
Lisa
Regarding my previous questions, I just wanted to let you know that I now have an appropriate model formulation of the CVRP with subtour elimination that works and provides an optimal result.
The above questions are therefore no longer relevant for me personally.
If anyone is interested in the model formulation, please feel free to get back to me.
Best regards
Lisa
Re: Capacitated Vehicle Routing Problem
Hi Liza,
i'm currently also working at this problem.. but with no success until now.
Would you like to share your solution with me?
Thx and best regards !
i'm currently also working at this problem.. but with no success until now.
Would you like to share your solution with me?
Thx and best regards !
Re: Capacitated Vehicle Routing Problem
Hello Gamsbart,
If it is not too late and you are still working on the model, you will find my version of the CVRP below:
Maybe it will help you. I have managed to avoid subtours and it also gives the correct optimal solution.
In case of questions, feel free to come back to me.
Best regards
Liza
If it is not too late and you are still working on the model, you will find my version of the CVRP below:
Maybe it will help you. I have managed to avoid subtours and it also gives the correct optimal solution.
In case of questions, feel free to come back to me.
Best regards
Liza
Re: Capacitated Vehicle Routing Problem
Hi lisa,
Thank you so much for this amazing model. I have a question.
Why should individual vehicle capacities be equal to or greater than the demands of customer points?
Thanks,
Thank you so much for this amazing model. I have a question.
Why should individual vehicle capacities be equal to or greater than the demands of customer points?
Thanks,