SALOME: A Bidirectional Branch-and-Bound Procedure for Assembly Line Balancing

In this article, we report on new results for the well-known Simple Assembly Line Balancing Problem Type 1. For this NP-hard problem, a large number of exact and heuristic algorithms have been proposed in the last four decades. Recent research has led to efficient branch-and-bound procedures. Based on an analysis of their specific strengths, a new algorithm (Salome) is developed. Its main characteristic is a new branching strategy (local lower-bound method) and a bidirectional branching rule. Furthermore, new bounding and dominance rules are included. Computational experiments on the basis of former data sets, as well as a new, more challenging one, show that Salome outperforms the most effective existing procedures for solving this problem.