Routing Optimisation of Urban Medical Waste Recycling Network considering Differentiated Collection Strategy and Time Windows

Table 4

Comparison between CPLEX solver and PSO algorithm on small-scale instances.

Instance		CPLEX		PSO
Group	ID
ISG1	1	11	1.77	11	8.10	0.00%
	2	11	1.49	11	8.22	0.00%
	3	11	0.80	11	7.83	0.00%
	4	11	1.58	11	8.31	0.00%
	5	12	1.97	12	7.60	0.00%
ISG2	1	13	5.17	13	15.2	0.00%
	2	13	242.43	13	14.45	0.00%
	3	13	132.15	13	14.32	0.00%
	4	13	354.97	13	14.30	0.00%
	5	13	348.38	13	13.19	0.00%
ISG3	1	—	>7200	17	20.83	—
	2	—	>7200	17	21.38	—
	3	—	>7200	17	22.41	—
	4	—	>7200	17	20.79	—
	5	—	>7200	17	37.29	—
Average	—	—	—	—	15.61	—

Notes: (1) represents the optimal solution obtained by CPLEX. denotes the global best solution obtained by PSO algorithm. (2) and are the computation time of CPLEX and PSO algorithm in seconds, respectively. (3) .