Code: A Fast Exact Pricing Algorithm for the Railway Crew Scheduling Problem

This is a repository containing the code used for the article A Fast Exact Pricing Algorithm for the Railway Crew Scheduling Problem'. In this article, a new exact pricing algorithm is proposed, and this algorithm is compared to the fastest known exact algorithm from literature.

Abstract

The railway crew scheduling problem consists of selecting a least cost set of duties that cover all tasks. Large-scale crew scheduling problems are typically solved with column generation, where in each iteration a pricing problem needs to be solved. When the duty constraints consist in a maximum duty length, a meal break constraint, and the requirement to start and end at the same crew depot, the fastest known exact pricing algorithm has O(|N|³) complexity, |N| being the number of tasks. In this work we propose an O(|N|²) exact pricing algorithm. We compare the two algorithms on randomly generated instances and show that a reduction in computation time of 95% is attained on instances of size |N|=1,250.