A Heuristic Procedure for a Ship Routing and Scheduling Problem with Variable Speed and Discretized Time Windows

Table 4

Summary of results of instances of 50 Contracts.

Instance			CPLEX				Heuristic
Contracts	Ships	Nodes per window	Optimum Found	Only Feasible Solution	No Solution	Average Time (sec)	Solution not Found	Average Time (sec)	GAP; O.F. (%) Average
50	7	3	14	0	1	18.71	2	109.30	5.95
50	7	6	13	0	2	183.53	4	358.45	5.35
50	7	15	8	7	1	4291.85	2	1551.38	5.87
50	9	3	15	0	0	23.80	0	134.06	6.69
50	9	6	15	0	0	371.53	0	558.40	6.53
50	9	15	7	8	0	4450.20	0	2795.53	6.09