Yard Storage Assignment Optimisation with Neutral Walks

摘要

In this paper we investigate how to stack products on a storage yard for efficient retrieval. The objective is to minimise both the transport distance and the number of stack shuffles. Previous research on yard storage assignment indicated that the fitness landscape of the problem features a high degree of neutrality, meaning that there are many neighbouring solutions with identical objective value. We exploit this property and couple local search, tabu search and evolution strategy with neutral walks and extrema selection. A small benchmark instance can be solved to optimality with all three modified algorithm variants while the standard algorithms got stuck in local optima.