Average MILP and heuristic performance
| n | MILP (solved with Gurobi) | Heuristic | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Time | UB | LB | Gap | Un | Un pen | QRF | Route | Time | Obj | Un | Un pen | QRF | Route | |
| 3 | 23 | 5.19 | 5.19 | 0 | 0.0 | 0 | 0/10 | 3.79 | 3 | 5.35 | 0.0 | 0 | 0/10 | 3.95 |
| 4 | 1,455 | 5.94 | 5.94 | 0 | 0.0 | 0 | 0/10 | 4.24 | 7 | 5.99 | 0.0 | 0 | 0/10 | 4.29 |
| 5 | 9,278 | 6.68 | 6.68 | 0 | 0.0 | 0 | 0/10 | 4.88 | 9 | 6.68 | 0.0 | 0 | 0/10 | 5.03 |
| 6 | * | 7.51 | 7.51 | 0 | 0.0 | 0 | 0/10 | 5.71 | 14 | 47.64 | 0.1 | 40 | 0/10 | 5.84 |
| 7 | * | 8.77 | 8.77 | 0 | 0.0 | 0 | 0/10 | 6.77 | 18 | 8.99 | 0.0 | 0 | 0/10 | 6.99 |
| 8 | * | 18.74 | 18.74 | 0 | 0.1 | 10 | 0/10 | 6.84 | 41 | 79.28 | 0.2 | 30 | 1/10 | 7.48 |
| 9 | * | 49.37 | 8.91 | 82 | 0.0 | 0 | 1/10 | 7.05 | 56 | 69.08 | 0.5 | 60 | 0/10 | 7.08 |
| 10 | * | 49.66 | 9.15 | 82 | 0 | 0 | 1/10 | 7.66 | 84 | 60.31 | 0.1 | 10 | 1/10 | 8.41 |
| 20 | 21,600 | – | 1.98 | – | – | – | – | – | 789 | 2976.45 | 0.1 | 2,560 | 10/10 | 14.45 |
| 30 | 21,600 | – | 0.90 | – | – | – | – | – | 2,554 | 609.40 | 1.1 | 190 | 10/10 | 17.40 |
| MILP (solved with Gurobi) | Heuristic | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Time | UB | LB | Gap | Un | Un pen | QRF | Route | Time | Obj | Un | Un pen | QRF | Route | |
| 3 | 23 | 5.19 | 5.19 | 0 | 0.0 | 0 | 0/10 | 3.79 | 3 | 5.35 | 0.0 | 0 | 0/10 | 3.95 |
| 4 | 1,455 | 5.94 | 5.94 | 0 | 0.0 | 0 | 0/10 | 4.24 | 7 | 5.99 | 0.0 | 0 | 0/10 | 4.29 |
| 5 | 9,278 | 6.68 | 6.68 | 0 | 0.0 | 0 | 0/10 | 4.88 | 9 | 6.68 | 0.0 | 0 | 0/10 | 5.03 |
| 6 | * | 7.51 | 7.51 | 0 | 0.0 | 0 | 0/10 | 5.71 | 14 | 47.64 | 0.1 | 40 | 0/10 | 5.84 |
| 7 | * | 8.77 | 8.77 | 0 | 0.0 | 0 | 0/10 | 6.77 | 18 | 8.99 | 0.0 | 0 | 0/10 | 6.99 |
| 8 | * | 18.74 | 18.74 | 0 | 0.1 | 10 | 0/10 | 6.84 | 41 | 79.28 | 0.2 | 30 | 1/10 | 7.48 |
| 9 | * | 49.37 | 8.91 | 82 | 0.0 | 0 | 1/10 | 7.05 | 56 | 69.08 | 0.5 | 60 | 0/10 | 7.08 |
| 10 | * | 49.66 | 9.15 | 82 | 0 | 0 | 1/10 | 7.66 | 84 | 60.31 | 0.1 | 10 | 1/10 | 8.41 |
| 20 | 21,600 | – | 1.98 | – | – | – | – | – | 789 | 2976.45 | 0.1 | 2,560 | 10/10 | 14.45 |
| 30 | 21,600 | – | 0.90 | – | – | – | – | – | 2,554 | 609.40 | 1.1 | 190 | 10/10 | 17.40 |
Note(s): * Alternative MILP solution method used
− Gurobi was not able to find values
See Table A2 for instance-level details
Source(s): Table by authors
Sharing content requires targeting cookies to be enabled. Please update your cookie preferences to use this feature.