The Annual Delivery Program (ADP) for Liquefied Natural Gas (LNG) represents a complex maritime inventory-routing problem requiring precise synchronization of production and distribution. This study introduces a novel Mixed-Integer Linear Programming (MILP) formulation designed to optimize vessel routing and scheduling over a one-year horizon under a direct-shipment assumption. The model minimizes total logistics costs, encompassing both fixed annual fleet costs and variable operational expenses. To ensure stability and prevent delivery clustering, customer demand is managed through discrete delivery frequency options that partition the year into specific windows. A key contribution of this work lies in the computational enhancement of the model, achieved by integrating multiple classes of valid inequalities and linearizing several sets of binary variables to improve solution efficiency.

Keywords

LNG Supply Chain, Annual Delivery Plan, Maritime Inventory Routing.