Table 3: Optimal solutions under different confidence levels.

Variable Item 1 Item 2 Item 3 Item 4 Item 5


182.5 0.54 1.62 0.84 0.073
210.7 0 0.58 0.84 6.29
0 0.560 0480.51


190.51 0.15 0.87 0.38 0.13
307.81 0 0.481 0.38 4.48
0 0.610 0489.71


198.05 0.058 0.42 0.33 0.081
395.29 0 0.409 0.33 2.58
0 0.420 0495.37


199.95 0.032 0.35 0.12 0.057
394.39 0 0.345 0.12 2.231
0 0.3480 0498.45

Note: and denote objective values of the upper level and lower level, respectively. and denote the production quantity by producer 1 and produce 2, respectively.