Solution strategy for inventory constrained maritime routing and scheduling: multi-commodity bulk shipping

Abstract

In recent years, as global distribution, overseas sourcing and overseas sales of various multinational companies have increased, efficient management of the global supply chain, which is one of the important research areas of international management, is required. Thus, ship routing and scheduling are important for the global Supply Chain Management (SCM). In this article, it deals with a solution algorithm that takes advantage of model properties for routing and scheduling problems on the maritime transport of liquid bulk products. It shows that the mixed-integer linear program can be decomposed into several sub-problems by dualising coupling constraints. Also, the minimisation problem solved by the Lagrangian Relaxation method to get a better lower bound in this article. The numerical studies to establish the goodness of the combined Lagrangian Relaxation and Dual Ascent method is conducted. The test results show an average duality gap of 26.8% and an average optimality gap of 12.5% on small sized problems. More importantly, the solution times are, on average, three orders of magnitude faster than getting a first feasible solution by CPLEX when using the default options of the solver. Copyright © 2024 Inderscience Enterprises Ltd.