Design models for unit load storage and retrieval systems using autonomous vehicle technology and resource conserving storage and dwell point policies

Computationally efficient design conceptualization models are proposed for automated unit load storage and retrieval systems based on autonomous vehicle technology. Vehicle and lift travel times and the probability distribution for 12 service scenarios occurring under realistic operating assumptions are formulated and used to generate expected transaction service times. Additional measures of system performance including transaction waiting time and vehicle utilization are formulated for systems using random storage and point-of-service-completion dwell point rules. The models provide a practical means of predicting key aspects of system performance based on five design variables that drive the majority of system costs. They are illustrated in the context of a conceptualization study adapted from an actual system installation.