A Hybrid Genetic Algorithm to Minimize Total Tardiness for Unrelated Parallel Machine Scheduling with Precedence Constraints

Table 4

Performance of the HGA for small-sized instances.

No. of group	𝐷=0.5; 𝜌=0.5; RD=0.1; 𝑝𝑗𝑣∼[1,10]		B&B		HGA
	𝑛	𝑚	𝑓BB	Mean CPU time (s)	𝑓HGA	Mean CPU time (s)	Gap (%)
1	9	4	39	1.5	39	0.4	0
2	9	3	72	5.5	72	0.6	0
3	9	2	61	72.7	61	0.7	0
4	10	4	68	9.3	68	7.1	0
5	10	3	63	2.9	63	5.7	0
6	10	2	64	18.7	65	8.4	1.6
7	11	4	32	86.2	32	2,3	0
8	11	3	123	2.8	124	0.6	0.8
9	11	2	129	20.5	129	1.9	0
Average				24.5		3.1	0.3