Column Generation for a Multitrip Vehicle Routing Problem with Time Windows, Driver Work Hours, and Heterogeneous Fleet

Table 2

Results obtained for R2 instances with the first 50 customers.

Instance	Customer qty.	Route qty.	Heuristic cost	Heuristic time (s)	Lower bound	Lower bound time (s)	Heuristic error (%)	Iterations
R201	50	1	629.643	323	617.533	3	1.923	56
R202	50	1	580.792	388	540.406	758	6.954	60
R203	50	1	542.673	892	515.961	33367	4.922	88
R204	50	1	504.971	1050	*	*	*	*
R205	50	1	582.809	423	563.371	41	3.335	83
R206	50	1	548.465	541	529.240	520	3.505	83
R207	50	1	522.382	557	*	*	*	*
R208	50	1	508.412	1090	*	*	*	*
R209	50	1	543.668	833	526.939	814	3.077	75
R210	50	1	556.702	532	532.627	493	4.325	76
R211	50	1	514.903	985	489.296	4843	4.973	92
			548.675	692	539.422	5105	4.127	77
R201	50	2	631.263	521	617.533	6	2.175	83
R202	50	2	584.234	603	552.827	2712	5.376	88
R203	50	2	547.387	726	*	*	*	*
R204	50	2	516.083	832	*	*	*	*
R205	50	2	585.736	660	563.292	213	3.832	90
R206	50	2	546.744	680	527.546	5298	3.511	92
R207	50	2	523.277	771	*	*	*	*
R208	50	2	509.368	851	*	*	*	*
R209	50	2	552.351	1224	519.866	2944	5.881	94
R210	50	2	559.125	655	530.574	2736	5.106	87
R211	50	2	524.933	776	491.795	22175	6.313	105
			552.773	754	543.348	5155	4.599	91
R201	50	3	637.648	655	617.533	18	3.155	91
R202	50	3	581.999	756	555.689	8441	4.521	91
R203	50	3	546.259	871	*	*	*	*
R204	50	3	514.158	1002	*	*	*	*
R205	50	3	585.951	823	562.820	1051	3.948	84
R206	50	3	552.396	825	526.078	25137	4.764	95
R207	50	3	531.691	880	*	*	*	*
R208	50	3	507.904	1039	*	*	*	*
R209	50	3	550.108	854	517.297	7351	5.964	101
R210	50	3	559.496	859	534.958	18095	4.386	91
R211	50	3	524.667	954	494.806	92018	5.691	109
			553.843	865	544.169	21730	4.633	95

Value of cells marked with * were not computed due to an overall time greater than 93000 s.