Routing-based Sequencing Applied to Shuttle Systems

Shuttle systems are automated storage and retrieval systems based on autonomous vehicles moving within a storage-rack system. Various shuttle system configurations exist, which differ by the vehicles' movement axes. Some configurations allow stored units to be retrieved in a given sequence directly from the storage system. Supplying picking areas in customer-order sequence or production areas in production sequence exemplify the requirement to supply storage items in a particular sequence. In this contribution., we apply a routing-based algorithm to shuttle systems., which ensures that routed vehicles arrive in a desired sequence. We conduct a series of simulation experiments to analyze the impact of retrieval-in-sequence on throughput and discuss measures to mitigate the ensuing loss of throughput.