Fully Fuzzy Multi-objective Berth Allocation Problem.

The Berth Allocation (BA) problem is an important problem in port logistics. It aims at finding optimal berthing times and positions of arriving vessels in a wharf subject to physical constraints. The optimisation criteria in the BA problem are diverse and respond to specific interests of vessels and wharves operators. Furthermore, although the BA problem has been dealt with mostly under complete certainty, it is a highly uncertain problem due to many factors that can affect vessels arrival and handling times. This paper takes fuzzy uncertainty into account and presents a fully fuzzy two-objective BA problem, by considering the minimisation of the total waiting time of vessels and the makespan of the wharf operation from the perspectives of vessels and wharves operators, respectively. A fuzzy epsilon-constraint method and a lexicographic method for fully fuzzy linear programming with inequality constraints are used jointly to solve the problem. A numerical example is given as illustration. Results demonstrate the usefulness of the proposed approach in handling fuzziness and conflicting objectives simultaneously in a BA problem.