A Nonlinear Integer Programming Model for Integrated Location, Inventory, and Routing Decisions in a Closed-Loop Supply Chain

Table 8

Computational results for medium-size problems.

Instance name		HGSAA			IAGA			AHSAGA
		M1	SD	CV	M2	SD	CV	M3	SD	CV
Christofides69-50 × 5	Computational time	3.52	0.04	0.01	2.96	0.05	0.02	2.97	0.04	0.01	15.60%	−0.14%
	Convergence generation	185.52	118.83	0.64	179.58	114.49	0.64	173.90	106.46	0.61	6.26%	3.16%
	Total cost	64622673.96	4896193.44	0.08	65120367.91	4880581.60	0.07	63410536.90	4447087.25	0.07	1.88%	2.63%
Perl83-55 × 15	Computational time	4.55	0.04	0.01	4.14	0.06	0.01	4.09	0.05	0.01	10.01%	1.27%
	Convergence generation	202.68	120.89	0.60	199.34	117.33	0.59	194.64	114.00	0.59	3.97%	2.36%
	Total cost	75608999.15	4218565.18	0.06	75488435.46	4821373.57	0.06	74318631.82	3372606.19	0.05	1.71%	1.55%
Christofides69-75 × 10	Computational time	5.53	0.06	0.01	4.76	0.09	0.02\	4.80	0.05	0.01	13.24%	−0.73%
	Convergence generation	203.52	119.05	0.58	201.04	115.46	0.57	193.18	110.48	0.57	5.08%	3.91%
	Total cost	140932062.97	10696126.94	0.08	137838194.63	13260464.21	0.10	137205765.38	10092485.60	0.07	2.64%	0.46%
Perl83-85 × 7	Computational time	6.03	0.04	0.01	5.21	0.11	0.02	5.21	0.10	0.02	13.48%	−0.11%
	Convergence generation	211.78	119.39	0.56	186.32	113.21	0.61	182.14	102.34	0.56	14.00%	2.24%
	Total cost	407102768.27	10738366.84	0.03	404838974.84	12150698.81	0.03	404614214.54	9236869.46	0.02	0.61%	0.06%
Daskin95-88 × 8	Computational time	6.23	0.04	0.01	5.47	0.10	0.02	5.43	0.08	0.02	12.84%	0.75%
	Convergence generation	214.16	125.73	0.59	206.94	112.33	0.54	206.64	110.85	0.54	3.51%	0.14%
	Total cost	95326029.80	6322807.23	0.07	94077056.19	5903902.59	0.06	94002405.72	5837160.63	0.06	1.39%	0.08%