A comparison of separation routines for benders optimality cuts for two-level facility location problems.

•The two-level uncapacitated facility location problem is computationally studied.•Single and multiple allocation variants are analyzed.•Benders cut specialized separation procedures are devised for the problem variants.•Near Pareto-optimal cuts outperform the other proposed cut separation methods.•Large scale instances with up to 20,000 client nodes are solved to optimality.