“…The following fuzzy data are used for presenting the multi-echelon RL network design problem. Moreover, shipping cost ($) for one kg of recycled material from the recycling facilities to manufacturing plants are (5, 5.5, 6), (4.5, 5, 6.5), (5,6,7) and (4, 4.5, 5), respectively. Opening/operating costs and capacities of the facilities are also given in Table 10.…”