I have a problem solving the MILP problem written in attached file. I know that formulation is right, because it was solved with XPRESS commercial solver without any error or warning. But if I try to solve it with glpk it does not work. I also tried to change backtrack routines or some other MILP options, but it still does not wok. Is there any suggestion you coud give me? Or is it an hard problem for glpk (even if I don not think so)?
Economical-1.lp