Particle Swarm Optimization Algorithm for Unrelated Parallel Machine Scheduling with Release Dates

Table 2

The performance of heuristic SRD_Reassign for small problem instances.

4m18n	MIP		SRD_Reassign		FCFS
𝛼	Mean	Avg. time	Mean	Avg. time	Mean	Avg. time
0.10	1	1176.32	1.11	0.003	1.46	0.000
0.25	1	239.19	1.09	0.002	1.43	0.000
0.50	1	58.02	1.04	0.002	1.34	0.000
Average	1	491.18	1.08	0.002	1.41	0.000

Mean = average ratios of heuristic/MIP obtained from 20 instances.