A Hybrid Algorithm for the Permutation Flowshop Scheduling Problem without Intermediate Buffers

Table 1

Comparison results between VNS and SSVNS.

Problem ()	VNS1		SSVNS
	APRD	minPRD	APRD	minPRD
20 × 5	−0.43	−0.43	−0.43	−0.46
20 × 10	−2.29	−2.38	−2.38	−2.40
20 × 20	−2.96	−2.94	−3.22	−3.30
50 × 5	−2.19	−2.72	−4.06	−4.42
50 × 10	−4.02	−4.55	−4.85	−5.48
50 × 20	−4.92	−5.39	−5.18	−5.53
100 × 5	−2.37	−2.52	−2.32	−2.63
100 × 10	−4.36	−4.61	−5.11	−5.76
100 × 20	−3.72	−4.14	−4.02	−4.60
200 × 10	−2.71	−3.39	−3.10	−4.08
200 × 20	−2.77	−2.91	−3.28	−3.90
500 × 20	−1.36	−1.72	−1.82	−1.99
Average	−2.84	−3.14	−3.31	−3.71