A reduced integer programming model for the ferry scheduling problem

TL;DR

This paper introduces a more efficient integer programming model for ferry scheduling that reduces complexity and handles key operational constraints, demonstrating practical solution quality with real-world data.

Contribution

The paper presents a reduced-size integer programming model that efficiently incorporates load/unload, crew, and passenger transfer constraints for ferry scheduling.

Findings

High-quality solutions within 12 hours using CPLEX

Model reduces variables and constraints by approximately O(n)

Performance guarantee within 15% of optimality

Abstract

We present an integer programming model for the ferry scheduling problem, improving existing models in various ways. In particular, our model has reduced size in terms of the number of variables and constraints compared to existing models by a factor of approximately O(n), where n being the number of ports. The model also handles efficiently load/unload time constraints, crew scheduling and passenger transfers. Experiments using real world data produced high quality solutions in 12 hours using CPLEX 12.4 with a performance guarantee of within 15% of optimality, on average. This establishes that using a general purpose integer programming solver is a viable alternative in solving the ferry scheduling problem of moderate size.