Table 10 Performance of the improved exact algorithm by decreasing time complexity

Number of workers (W)

5

6

7

8

Number of all solutions (N)

541

4683

47,293

545,835

Left solutions (K)

48

852

2437

9749

Solutions cut off

493

3831

44,856

536,086

Ratio of solutions cut off (%)

91

82

95

98.2

Time of enumeration based-NS (second)

0.06

1.4

–

–

Time of NS in step (5) (second)

0.002

0.03

0.4

–

Total time of the improved algorithm(second)

0.035

0.28

2.87

–