Research Article

A Simulated Annealing Approach for the Train Design Optimization Problem

Table 8

Relevant data (columns I, II) and results (columns III, IV, and V) of 50 runs of SA on 20 random instances. A lower bound—explained in Section 5.3—on the optimal solution cost is shown in column VI. The last column is an indicator of the solution quality.

I II III IV V VI VII
Instance Number of
stations, blocks, arcs, crew segments
Minimum cost
()
Average cost Avg time
(sec)
Lower bound
()
Difference in %

p5_7D5 7 5 6 47,193 47,193 1 32,957 43.18
p5_10D5 10 4 6 77,691 77,726 1 60,336 28.76
p10_15D10 15 11 14 224,186 226,845 4 187,862 19.34
p10_20D10 20 8 13 294,595 299,021 4 248,649 18.48
p20_30D20 30 13 25 297,952 301,013 13 243,932 22.15

p20_40D20 40 15 25 336,651 339,876 13 267,840 25.69
p40_60D40 60 22 45 565,954 576,906 49 446,538 26.74
p40_80D40 80 21 45 568,089 573,991 46 446,411 27.26
p80_120D80 120 38 86 791,072 800,660 124 614,225 28.79
p80_160D80 160 38 89 987,646 997,005 168 791,041 24.85

p160_240D160 240 62 169 2,214,593 2,240,989 376 1,791,395 23.62
p160_320D160 320 72 169 2,201,347 2,221,606 320 1,765,637 24.68
p200_300D200 300 82 216 4,043,845 4,071,617 409 3,306,843 22.29
p200_400D200 400 81 210 1,591,058 1,607,980 463 1,203,586 32.19
p250_375D250 375 96 261 2,518,148 2,548,918 856 1,958,093 28.60

p250_500D250 500 104 260 1,881,881 1,905,522 723 1,445,175 30.22
p300_450D300 450 117 311 8,919,042 8,969,957 606 7,480,671 19.23
p300_600D300 600 115 313 10,419,523 10,453,791 744 8,782,219 18.64
p320_480D320 480 138 333 8,172,082 8,218,034 662 6,676,505 22.40
p320_640D320 640 138 332 2,053,295 2,077,627 900 1,516,815 35.37