Results
With the data in the model above, the column generation algorithm generates 6 new patterns, taking the value of the LP-relaxation of the cutting stock problem from originally 177.67 down to 160.95. The MIP finds a solution with 161 rolls using the following patterns:
| Widths | ||||||
|---|---|---|---|---|---|---|
| Pattern | 17 | 21 | 22.5 | 24 | 29.5 | Usage |
| 3 | 0 | 0 | 4 | 0 | 0 | 1 |
| 5 | 0 | 0 | 0 | 0 | 3 | 15 |
| 6 | 0 | 1 | 0 | 3 | 0 | 32 |
| 8 | 2 | 0 | 0 | 0 | 2 | 75 |
| 10 | 0 | 2 | 1 | 0 | 1 | 32 |
| 11 | 0 | 0 | 2 | 2 | 0 | 6 |