Table. 2.

Problem setting and instances

Classification of scale	Problem index	I	J	K	L	O	V	U
Small	P1	2	4	4	4	10	10	3
	P2	2	6	6	5	12	20	3
	P3	6	8	8	6	14	30	3
	P4	6	10	12	7	16	40	4
	P5	6	12	16	8	18	45	4
Medium	P6	10	12	20	10	20	60	4
	P7	10	12	26	10	22	70	6
	P8	10	14	32	10	24	80	6
	P9	10	14	38	11	26	90	6
	P10	10	16	44	12	28	100	8
Large	P11	15	20	50	14	30	130	8
	P12	15	22	54	15	32	150	8
	P13	15	24	60	16	34	160	10
	P14	15	26	70	17	36	170	10
	P15	15	30	80	18	38	200	10