Maritime Inventory Routing Problems

Abstract

Article Outline Abstract Introduction The Basic ISRP Problem Description Mathematical Model Extensions of the ISRP One Central Supplier or Consumer Inventory Constraints in Either Production Ports or Consumption Ports Variable Production or Consumption Rate Multiple Products Use of Spot Charters Combined Inventory Routing and Cargo Routing Combining Inventory Routing with Other Planning Aspects Concluding Remarks Acknowledgements References Abstract Maritime transportation is a heavily utilized mode when large quantities of bulk products need to be transported over long distances. Often, inventories exist at the loading and/or unloading ports of the sailing legs. When the ship operator has the responsibility for both the transportation of the fleet and the inventories at the ports, the underlying planning problem is a maritime inventory routing problem. Here we introduce the reader to various applications within maritime inventory routing and present some examples of research contributions. First we consider and present a mathematical model for the basic problem where a single product is transported and denote this problem the inventory ship routing problem . There exist a lot of extensions and variants of the problem. These include, among others, problems with inventories at only one end, variable production/consumption rates, multiple products, use of spot charters and problems that combine inventory routing with other planning aspects. Maritime inventory routing problems are very complex and to the authors' knowledge there exist no commercial optimization-based systems for the shipping industry yet. However, it is probably just a question of time before they become available.