Maritime inventory routing problems involve the coordination of vessel routing and inventory managment. Compared to road-based problems, maritime problems have several characteristics that make this integration relevant. The quantities transported are large, both in terms of vessel capacity and storage capacity at production and consumption facilities. In addition, travel times between facilities are considirable. This leads to a problem where routing decisions has a large impact on the inventory levels and vice versa.
Invent is a software library for solving maritime inventory problems. It also handles cases that involve tramp shipping, i.e. transportation demands that are not related to storage facilities. Common constraints, such as draft limits, onboard stowage and cleaning requirements between different products, are handled. For a full model specification, see this document.
The Invent library is built into a simple command line application that reads problem data from an XML file, creates and optimizes a solution, and writes the result to a new XML file. More advanced integration with other software components is straightforward. The system has been developed on Windows, and ports to other platforms will be made available on request.
Contact: Oddvar Kloster
Published October 20, 2010
