Exact and metaheuristic approaches to solve the integrated production scheduling, berth allocation and storage yard allocation problem

Abstract

This work studies an industrial complex specialized in producing and exporting fertilizers. The integration of the production scheduling, berth allocation, and storage yard allocation decisions is necessary to improve the overall performance of the complex as these problems are interrelated. Exact and metaheuristic approaches are proposed to solve the problem. First, a mixed-integer linear formulation along with a branch-and-cut procedure are proposed. The numerical experiments show that these exact methods solve small-sized instances optimally but fail to provide good quality solutions for industrial-sized instances. Therefore, a multi-start GRASP-ILS is proposed where initial solutions are constructed using a greedy randomized adaptive search procedure (GRASP) and improved using an iterated local search algorithm (ILS). The metaheuristic approach is based on a disjunctive graph representation and additional conditions to respect the storage yard constraints and other operational constraints. The results show that the multi-start GRASP-ILS can be effectively used to solve larger instances of the problem.