Algorithm 4. Repair (T level_max, $N_i$(I = 1,…,7)).

Require: T, level_max, $N_i$(i = 1,…,7) are the infeasible solution, the parameter to control the strength of the perturbation procedure, and the number of neighbourhood respectively.

Ensure: An feasible solution T.

1: level = 1;

2: while ((T is infeasible solution) and (level $\le$ level_max)) do

3: $T^{{}^{\prime }}$= Perturbation(T, level);

4: for $i:1\to 6$ do

5: $T^{{}^{″}}\leftarrow \mathrm{a}\mathrm{r}\mathrm{g}min{N}_i(T^{{}^{\prime }});$ {local search}

6: if $(L(T^{{}^{″}}<L(T^{{}^{\prime }}))$ then

7: $T^{{}^{\prime }}\leftarrow T^{{}^{″}}$

8: $i\leftarrow 1$

9: else

10: $i++$

11: if $L(T^{{}^{\prime }})<L(T)$ then

12: $T\leftarrow T^{{}^{\prime }};$

13: if $L(T^{{}^{\prime }})==L(T)$ then

14: $level\leftarrow 1;$

15: else

16: $level++;$

17: return T;