New VRP Problem Instances

[salma amali]

hello;

I created a new problem instance variant based on the ( creat new problem instance) tutorial but I derived my problem from the MDCVRPTW variant.

 however I have a constraint that the duration of all tours must not exceed 45 minutes 

 Please help me a way forward(add this constraint to my new variant).

thanks

salma

[Andreas Beham]

I think you can solve that by introducing a respective due time at the depot.

[salma amali]

Hello Andreas,

Thanks for your responsiveness,

I still disturbing you with my questions

1- does the problem take into account the speed of the vehicle or do I have to add a new  travel times matrix where I specify the duration between cities? 

2- you told me to enter 45 min as a due time at the depot but for the cities  should  i put 0 or leave them empty

Thanks  

[Andreas Beham]

1) Sorry, I assumed you already have a matrix with the travel times.

The standard "distance matrix" is often in a time unit in VRPTW because time windows and service times are also compared respectively added to the "distance". If you just had distances, I would suggest to use times instead. If you need the distance, maybe add that as a new matrix, e.g. when you have a distance constraint.

2) The customers have as time window earliest 0, due date could also be 45 minutes or even slightly less if you take into account that the vehicle needs to arrive in time at the depot before 45 minutes.

[salma amali]

thank you for your answer

how I can add these travel time values to my variant, especially to distance matrix 

[Andreas Beham]

In the parameters of the problem instance there is a parameter called "DistanceMatrix". There you put the travel times.

[salma amali]

I think that the first n columns are for the travel times between the n depots and the other cities ?

[Andreas Beham]

The order has to be the same as in the other arrays (DueTime and ReadyTime). ServiceTime and Demand are without depots.