Harrington Park, NJ — December 20, 2025 — We successfully solved the MIPLIB 2017 benchmark instance bley_xs1.mps, finding a solution with objective value 3,855,895.86 and proving it optimal (0% optimality gap) using ODH|Xpress (https://miplib.zib.de/instance_details_bley_xs1.html).

MIPLIB instances are widely used as demanding, standardized benchmarks for mixed-integer programming (MIP). Achieving a provably optimal solution on these models demonstrates both modeling rigor and strong solver performance under benchmark conditions.

“This result underscores our ability to tackle difficult mixed-integer optimization problems and to deliver not only high-quality solutions, but also formal optimality proofs,” said Robert Ashford, Optimization Direct’s CEO.

Result Summary

• Benchmark: MIPLIB 2017
• Instance: bley_xs1.mps
• Objective value: 3,855,895.86
• Optimality gap: 0% (proven optimal)
• Solver: ODH|Xpress