Originally posted by: RithulKrishnan

Hi,

I upgraded my RAM from 8GB to 16GB and ran the TSP formulation (example problem) using the IBM ILOG IDE for a problem size of 142 components, and  it has taken 7 minutes. Is this normal? I was under the impression that it would take around 3-4 days. Also, when I run the berlin52.dat, the IDE solves in 0.64 seconds, whereas gr17.dat solves in 5 seconds. How is this possible, how can it take lesser time to solve a larger sized problem.

Thank you,

Rithul

Since these are NP hard problems size does not necessarily matter. There are small MIPs (only a few variables/constraints) that do not solve within hours, days, or weeks, and there are large MIPs (millions of variables/constraints) that solve within seconds.

Originally posted by: RithulKrishnan

Thank you Daniel. Also, I was working on a Capacitated VRP, with one vehicle with a capacity of 18, one depot,  but am not able to code it using the IDE. Can you please help me out with the formulation?  

I or other people on this Forum may be able to help you. But in order to do that you would have to ask a much more precise question. What exactly is your problem? What did you try so far? How does your model look like and where are you stuck?

Also, you should start a new thread for this question since it is completely unrelated to the topic (computation time) we discussed above.

Originally posted by: RithulKrishnan

Thank you! I will post whatever I have so far in a new topic. Your help is much appreciated.