Research Article

Lagrangian Relaxation for an Inventory Location Problem with Periodic Inventory Control and Stochastic Capacity Constraints

Table 11

Results for the second relaxation, R=1 and QCap=600.

Prob no.FCFVDCs opened ()DCs closed ()No. of open DCsUpper BoundLower Bound% GapLag iterCPU time (s)

1480.70.71185 2,023,248 2,004,405 0.941330103
1490.70.820None6 2,041,897 2,024,218 0.871344138
1500.70.920None6 2,056,136 2,041,853 0.70999106
1510.71.020None6 2,070,318 2,058,653 0.571372206
1520.71.114,20106 2,093,276 2,070,168 1.123156375
1530.71.212,14,2037 2,113,500 2,086,609 1.291680198
1540.71.320None6 2,120,860 2,104,350 0.781025124
1550.80.7NoneNone5 2,068,799 2,051,220 0.86101779
1560.80.813,14,203,56 2,096,264 2,072,203 1.161186110
1570.80.9NoneNone5 2,109,062 2,091,920 0.8285992
1580.81.020None6 2,126,971 2,108,184 0.891283145
1590.81.114,20106 2,140,929 2,125,481 0.73895105
1600.81.214,20106 2,154,840 2,144,731 0.47907112
1610.81.320None6 2,171,699 2,162,440 0.431071123
1620.90.7NoneNone5 2,115,023 2,087,493 1.321693133
1630.90.814105 2,138,568 2,110,547 1.33110586
1640.90.9NoneNone5 2,155,285 2,136,130 0.9088169
1650.91.014105 2,175,811 2,155,991 0.9289097
1660.91.114,20106 2,195,839 2,178,961 0.771759194
1670.91.214,20106 2,209,749 2,194,826 0.6886593
1680.91.320None6 2,231,671 2,214,517 0.77948100
1691.00.7NoneNone5 2,161,246 2,126,896 1.62107183
1701.00.814105 2,184,295 2,151,423 1.53109283
1711.00.9NoneNone5 2,201,509 2,175,341 1.2098476
1721.01.02, 3, 5, 8, 10N/A5 2,222,254 2,197,156 1.1481865
1731.01.114105 2,257,526 2,219,496 1.7181886
1741.01.214,20106 2,264,658 2,241,920 1.0182391
1751.01.314105 2,285,395 2,264,942 0.9086797
1761.10.7NoneNone5 2,207,470 2,165,608 1.93122598
1771.10.814105 2,230,023 2,191,819 1.7483166
1781.10.9NoneNone5 2,247,732 2,214,688 1.4980854
1791.11.014105 2,267,266 2,244,320 1.02106085
1801.11.114105 2,303,254 2,264,255 1.7280683
1811.11.214105 2,319,191 2,292,148 1.18877106
1821.11.314105 2,331,122 2,308,181 0.99925108
1831.20.7NoneNone5 2,253,693 2,203,834 2.26131488
1841.20.8NoneNone5 2,283,055 2,231,213 2.321341102
1851.20.9NoneNone5 2,293,956 2,252,404 1.8482754
1861.21.0NoneNone5 2,314,701 2,283,059 1.3981564
1871.21.1NoneNone5 2,346,628 2,307,932 1.6880970
1881.21.212, 143,105 2,363,777 2,336,492 1.1784590
1891.21.314105 2,376,850 2,354,471 0.95833113
1901.30.714105 2,299,884 2,242,034 2.58127784
1911.30.8NoneNone5 2,329,278 2,270,847 2.5778150
1921.30.9NoneNone5 2,340,179 2,298,306 1.82121176
1931.31.0NoneNone5 2,360,924 2,310,342 2.1977349
1941.31.1NoneNone5 2,392,852 2,346,581 1.9779750
1951.31.214105 2,410,646 2,371,311 1.6683953
1961.31.314105 2,422,577 2,400,707 0.9185554

(): with respect to base case, Prob no 172; N/A, not applicable.