A Genetic Algorithm for a Two-Machine Flowshop with a Limited Waiting Time Constraint and Sequence-Dependent Setup Times

Table 6

Performance of the heuristic algorithms (versus CPLEX).

Algorithm		10	15	20	Avg, sum
EDD	0.97, 0^a	2.07, 0	10.58, 0	4.52, 0	4.53, 0
MEDD	0.30, 9	1.1, 0	4.69, 0	2.03, 0	2.03, 9
Slack	0.88, 3	1.48, 0	6.17, 0	2.73, 0	2.81, 3
Greedy	0.44, 9	1.02, 0	4.39, 0	2.25, 0	2.02, 9
	0.06, 29	0.17, 9	0.71, 0	0.25, 0	0.3, 40
	0.05, 31	0.16, 7	0.66, 0	0.26, 2	0.28, 40
	0.04, 32	0.21, 7	0.71, 0	0.3, 1	0.31, 40
	0.08, 29	0.28, 1	1.52, 0	0.38, 0	0.56, 31

^aAverage error gap, number of instances (out of 45 instances) for which the algorithm found solutions better than or equal to those from CPLEX.