Table 1.
Results obtained by our ILP approach on instances with regular department lengths using Gurobi 6.5 [37] restricted to one thread on our machine with a time limit of 24 h. The running times are given in sec or in h:min:sec respectively.
| Instance | Lower bound | Upper bound | Gap in % | Time | B&B nodes |
|---|---|---|---|---|---|
| P15 | 189 | 189 | 0.0 | 30 | 15360 |
| P17 | 675.5 | 675.5 | 0.0 | 1:59:00 | 2368737 |
| P18 | 679.5 | 679.5 | 0.0 | 3:05:00 | 3241655 |
| H_20 | 710 | 710 | 0.0 | 5:30:00 | 4767725 |
| N25_05 | 368 | 368 | 0.0 | 17:00:00 | 3885648 |
| H_30 | 645 | 1441 | 55.2 | 24:00:00 | 1593134 |
| N30_05 | 973.5 | 3224.5 | 68.8 | 24:00:00 | 1514491 |
| Am33_03 | 600.5 | 1898.5 | 86.4 | 24:00:00 | 106547 |
| Am35_03 | 185.5 | 2132.5 | 91.3 | 24:00:00 | 210111 |
| ste36.5 | 1444 | 1444 | 0.0 | 1:24:00 | 38781 |
| N40_5 | 81 | 2772 | 97.1 | 24:00:00 | 42135 |
| sko42-5 | 84 | 4059 | 97.9 | 24:00:00 | 27352 |