I am developing a mixed-integer linear program (MILP) for a lane reservation problem. I solved a small case with Lingo, but it was infeasible (though I know it should be feasible). Why is this happening? Are some of the constraints too tight? Or maybe there are some logical mistakes in the model?
The model is provided in the link, below. $x_{ij},y_{ij}$ and $z_{ijk}$ are 0-1 decision variables
Any help or suggestions would be appreciated!
If you know that the small example should be feasible, does that mean you know a feasible solution for it? When you know a feasible solution, the easiest way to diagnose the problem is to substitute that feasible solution into the model and look for one or more constraints that are violated by it.