# Tag Info

### Feeding known lower bounds to solvers

Interesting topic (the question was raised several times by my students as well). My short answer is that adding the lower bound through a cut seems a good idea at first glance, but it creates a ...
• 1,616
Accepted

### How to compare two different formulations of a problem?

Even if the decision variables differ, you may still be able to prove that one of the formulations is stronger than the other by introducing an appropriate mapping. Take for example a flow ...
• 5,893

### Variable fixing based on a good feasible solution

A similar idea as suggested by @ RolfvanLieshout uses Lagrangian duals instead of LP duals, in a Lagrangian-based branch-and-bound scheme. For example, in the uncapacitated fixed-charge location ...
• 12.6k
Accepted

### Variable fixing based on a good feasible solution

As far as I know, it is not possible to fix any variables solely based on a feasible solution without compromising the exactness of your solution method. However, variable fixing is possible when you ...
• 2,254

### How to compare two different formulations of a problem?

I'm not sure there is a single, definitive best way to compare models, and if there is I likely have never seen it applied. I lean toward computational comparisons if properly done, but "properly done"...
• 31.1k