Tree search algorithms for the Sequential Ordering Problem

TL;DR

This paper introduces a simple, competitive iterative Beam Search algorithm for the Sequential Ordering Problem, combining dynamic programming cuts, which achieves optimality on many instances and improves solutions on open benchmarks.

Contribution

The paper proposes a novel iterative Beam Search algorithm with dynamic programming cuts for the Sequential Ordering Problem, demonstrating competitive performance and new best solutions.

Findings

Proves optimality on half of the SOPLIB instances.

Finds new best solutions on 6 out of 7 open instances.

Operates efficiently in small time frames.

Abstract

We present a study of several generic tree search techniques applied to the Sequential Ordering Problem. This study enables us to propose a simple and competitive tree search algorithm. It consists of an iterative Beam Search algorithm that favors search over inference and integrates dynamic programming inspired cuts. It proves optimality on half of the SOPLIB instances and finds new best known solutions on 6 among 7 open instances of the benchmark in a small amount of time.