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

Table 6

Computational results on Gaskell67-21 × 5.

Instance name		HGSAA			IAGA			AHSAGA
		M1	SD	CV	M2	SD	CV	M3	SD	CV
Gaskell67-21 × 5	Computational time	2.09	0.02	0.01	1.85	0.03	0.02	1.76	0.02	0.01	15.59%	4.80%
	Convergence generation	221.22	121.62	0.55	211.02	112.90	0.54	202.18	107.53	0.53	8.61%	4.19%
	Total cost	50860938.99	2778602.09	0.05	50276017.05	2991285.98	0.06	49977998.24	2709926.51	0.05	1.74%	0.59%

Remark: in Table 6, M1, M2, and M3 represent the mean objective values obtained by HGSAA, IAGA, and AHSAGA, respectively. SD means standard deviation, and CV means coefficient of variation. The same convention will also be used in the subsequent tables.