Performance comparison between Highs MIP solver and Schedule Nurse

 We compared Highs MIP solver and Schedule Nurse, using instances of Nurse Rostering Benchmarks site. Actually algorithm 2 in Schedule Nurse  is Highs MIP solver ,and algorithm 3 in Schedule Nurse is mathematical solver for nurse rostering benchmark use. Therefore we can fairly compare the performance under the all the same condition.

What is surprising is the significant improvement of the MIP solver in Highs. I think that Instance 8 was not solved in the previous test (two years ago), but it was solved this time. That is better than SCIP. As it has not yet been multi-threaded, we can expect further performance improvements in the future.