A solution framework for the integrated problem of cargo assignment, fleet sizing, and delivery planning in offshore logistics

Abstract

In order to support deep-sea oil and gas exploration and production operations, platform supply vessel plays a critical role, being the main transport resource to meet the demand of supplies ordered by maritime units. This leads to problems in efficiently allocating supplies to vessels and cost-effectively assessing the fleet size. Aiming to solve these problems, we propose a framework based on the integration of a mixed-integer programming model, which selects the supply set each vessel should provide, and a discrete-event simulator, which realistically represents the offshore operation scenario. We evaluate different fleet management policies, such as distinguishing parts of a fleet with respect to commodity type and multi-commodity transportation. In addition, we analyze the cargo allocation and vessel assignment along scheduled trips, comparing the traditional first-in-first-out delivery strategy with a completely optimization-centered alternative. Our study presents good-quality solutions that can potentially enhance offshore service levels, reduce fleet requirement, and decrease operational costs. We also demonstrate that our framework promotes a further step for improving the current logistics practices of a major oil company operating in Brazilian oil and gas offshore basins.