Future-proof ship pipe routing: navigating the energy transition

TL;DR

This paper introduces a mathematical framework for pipe routing in ships that accounts for fuel type uncertainty, using stochastic and robust optimization to reduce costs during the energy transition.

Contribution

It develops and adapts integer linear optimization models for uncertain pipe routing in maritime ships, addressing a previously overlooked aspect of future-proofing.

Findings

Cost reductions of up to 22% with stochastic and robust models

Models outperform deterministic approaches under uncertainty

Validated on artificial and real-world instances

Abstract

The maritime industry must prepare for the energy transition from fossil fuels to sustainable alternatives. Making ships future-proof is necessary given their long lifetime, but it is also complex because the future fuel type is uncertain. Within this uncertainty, one typically overlooks pipe routing, although it is a crucial driver for design time and costs. Therefore, we propose a mathematical approach for modeling uncertainty in pipe routing with deterministic, stochastic, and robust optimization. All three models are based on state-of-the-art integer linear optimization models for the Stochastic Steiner Forest Problem and adjusted to the maritime domain using specific constraints for pipe routing. We compare the models using both artificial and realistic instances and show that considering uncertainty using stochastic optimization and robust optimization leads to cost reductions of up to 22% in our experiments.