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

Table 4

The performance of PSO for small problem instances.

4𝑚18𝑛	MIP		PSO		SA		PSO/SA
𝛼	Mean	Avg. time	Mean	Avg. time	Mean	Avg. time
0.10	1	1176.32	1.00	11.73	1.05	12.79	11/0
0.25	1	239.19	1.00	10.69	1.06	12.17	18/0
0.50	1	58.02	1.00	8.69	1.03	10.28	10/0
Average	1	491.18	1.00	10.37	1.05	11.75	13/0

Mean = average ratios of algorithm/MIP obtained in 20 instances.