Research Article

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

Table 13

Results for the second relaxation, R=3 and QCap=600; QCap=900.

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

2460.70.7None1211 2,762,632 2,624,245 5.2781351
2470.70.811612 2,821,579 2,667,098 5.791700102
2480.70.911912 2,852,741 2,699,063 5.691800109
2490.71.011212 2,902,314 2,738,089 6.001653102
2500.71.111112 2,924,387 2,767,645 5.661674101
2510.71.215None13 2,988,536 2,808,140 6.42152694
2520.71.315None13 3,028,174 2,839,398 6.65153494
2530.80.7712,1611 2,860,498 2,719,105 5.2085154
2540.80.8None1911 2,919,636 2,764,674 5.612577153
2550.80.911912 2,965,225 2,797,354 6.001691101
2560.81.011212 3,017,797 2,839,010 6.301703102
2570.81.111112 3,038,856 2,869,832 5.891917123
2580.81.215None13 3,111,402 2,913,305 6.80143686
2590.81.37,151613 3,136,899 2,946,396 6.47159995
2600.90.7None1211 2,972,986 2,814,084 5.65124079
2610.90.8None1911 3,021,814 2,862,296 5.571713107
2620.90.911912 3,077,708 2,895,100 6.312142134
2630.91.011212 3,133,280 2,939,919 6.581595105
2640.91.111112 3,153,325 2,972,015 6.101771119
2650.91.215None13 3,234,269 3,018,470 7.15149197
2660.91.315None13 3,273,907 3,053,394 7.221687108
2671.00.7712,1611 3,071,115 2,908,436 5.59146394
2681.00.81510,1611 3,122,842 2,956,507 5.632108129
2691.00.911912 3,190,192 2,993,937 6.561776113
2701.01.02,3,5,8,10,11,12 13,14,16,19,20N/A12 3,241,325 3,040,813 6.59157498
2711.01.111112 3,267,793 3,074,195 6.30149790
2721.01.215None13 3,357,135 3,123,635 7.481793106
2731.01.315None13 3,396,774 3,160,391 7.48142883
2741.10.7712,1611 3,176,424 3,006,561 5.651631102
2751.10.8None1211 3,243,314 3,054,626 6.182187134
2761.10.911912 3,302,676 3,092,207 6.811806110
2771.11.011212 3,364,246 3,141,710 7.08161097
2781.11.115312 3,377,059 3,176,389 6.32135083
2791.11.21,151913 3,479,214 3,228,800 7.761691100
2801.11.315None13 3,519,640 3,267,390 7.721667100
2811.20.7None1611 3,268,978 3,101,566 5.401734107
2821.20.8None1911 3,328,346 3,152,607 5.57164599
2831.20.911912 3,415,160 3,190,419 7.041772110
2841.21.011212 3,479,729 3,242,618 7.311715107
2851.21.115312 3,489,521 3,278,575 6.43154297
2861.21.21,151913 3,600,037 3,333,966 7.98142883
2871.21.315None13 3,642,507 3,374,388 7.95149186
2881.30.713,1911 3,389,315 3,194,564 6.101805108
2891.30.8None1911 3,430,524 3,248,659 5.601706101
2901.30.911912 3,527,644 3,288,238 7.28158994
2911.31.0151612 3,592,914 3,343,519 7.46153991
2921.31.1151112 3,618,080 3,380,594 7.02163097
2931.31.21,151913 3,720,860 3,439,130 8.19154988
2941.31.31,151913 3,761,791 3,481,305 8.061666101

(): with respect to base case, Prob no 270; N/A, not applicable.