week_length = 7;
nb_workers = 25;
min_daysoff = 2;
max_daysoff = 3;
min_work = 4;
max_work = 7;
nb_shifts = 2;
temp_req = [| 11, 10, 10, 10, 10, 3, 3
            | 11, 10, 10, 10, 10, 3, 3 |];
shift_name = ["D", "A"];
shift_start = [360, 840];
shift_length = [480, 480];
shift_block_min = [2, 2];
shift_block_max = [6, 4];
nb_forbidden = 1;
forbidden_before = [2];
forbidden_after = [1];
forbidden_daysoff = [false];