Solution Strategies for a Multiport Container Ship Stowage Problem

Table 3

Comparing local search procedures on both sets grouped by number of ports. Column # shows the number of instances tested in each group, and column # Z shows the total number of solutions found with 0 reshuffles. The average number of reshuffles and average time in seconds are expressed in columns Res. and CPU.

		LSI			LSII
N	#	# Z	Resh.	CPU	# Z	Resh.	CPU
Set I
4	95	94	0.01	8.68	91	0.04	13.68
6	95	83	0.20	51.25	86	0.13	37.82
8	95	89	0.11	44.60	93	0.03	17.85
10	95	55	0.76	169.43	74	0.40	93.59
12	95	40	1.61	193.09	50	1.20	161.20
14	95	23	3.18	252.07	28	2.32	235.39
16	95	11	4.15	274.81	20	2.97	252.85
18	95	4	5.73	290.97	11	4.14	279.48
20	95	1	8.19	299.35	2	6.28	296.89
22	95	1	9.21	298.85	3	7.39	295.80
Total	950	401	3.31	188.31	458	2.49	168.46
Set II
4	120	115	0.07	0.00	115	0.07	0.00
6	120	78	0.81	0.08	81	0.79	0.01
8	120	53	1.69	0.60	54	1.79	0.12
10	120	16	3.81	3.10	14	4.01	0.79
12	120	6	6.00	5.90	7	6.02	1.66
14	120	4	8.76	7.77	4	8.74	2.65
16	120	0	12.71	15.22	1	13.08	4.00
Total	840	272	4.83	4.67	276	4.93	1.32