Modeling Multilevel Supplier Selection Problem Based on Weighted-Directed Network and Its Solution

Table 1

The simulation results for different scale problems.

The average values of 10 experiments
Network scale	Algorithm	Minimum	Maximum	Average	Variance	Convergence frequency
16 nodes	Ant colony	74.43	80.81	74.54	0.48	207.08
	Tabu search	74.08	104.70	80.20	3.18	515.00
30 nodes	Ant colony	425.8	491.48	426.44	2.6956	530
	Tabu search	436.5	532.2	481	19.39	375.00
50 nodes	Ant colony	7560.50	9041.10	7609.10	105.79	910.00
	Tabu search	8238.20	9187.80	8641.20	154.64	44.00
60 nodes	Ant colony	62.72	71.90	62.78	0.31	150.00
	Tabu search	73.93	89.98	80.88	2.55	243.33
70 nodes	Ant colony	68.35	87.12	68.52	0.51	700.00
	Tabu search	71.58	87.53	82.24	2.38	16.67
80 nodes	Ant colony	69.22	83.71	69.52	0.78	900.00
	Tabu search	83.94	95.17	90.06	91.06	92.06
90 nodes	Ant colony	82.32	101.20	83.05	0.74	1966.67
	Tabu search	90.74	104.30	97.97	2.23	750.00
100 nodes	Ant colony	81.38	101.55	81.71	0.57	1340.00
	Tabu search	89.26	106.90	100.10	0.39	1900.00