I've been solving a class of binary linear programming (BLP) problems with no objective function. I seek a single feasible solution. I've found acceptable runtimes using Gurobi v 10.0 when I use the NoRelHeurTime for appropriate values that are problem specific. (I also set MIPFocus = 1 and SolutionLimit = 1, although I don't think these parameters help that much if at all.) Without setting this parameter the runtimes are often very long.
My first question is, what exactly is Gurobi doing in the NoRel phase of the solution? How is this different from the Branch-&-Bound (B&B) solution techniques?
My 2nd question is as follows: I have a VERY large BLP problem (> 10^6 unknowns) that was not solved in over 6 months (I was not using the NoRelHeurTime parameter). I suspect my problems scale so badly that the B&B might run for years without finding a solution. Is there a chance that if I set NoRelHeurTime to infinity I might get a solution in a reasonable amount of time? I thought this might be worth a try as the NoRel phase of the solution process is fundamentally different from the B&B phase.
Please sign in to leave a comment.