AS/RS single command and dual command travel time analytical model for 3 class-based storage allocation

This paper presents an analytical model for the computation of travel time for Automated Storage and Retrieval Systems (AS/RS) with a three (ABC) class based storage in a rectangular in time warehouse. In particular, the authors provide the method for the analytical closed form evaluation of the expected mean travel time for the single, dual command cycles in the configuration with the input/output located in the bottom/left corner of the warehouse and varying the ABC curve. A numerical simulation analysis adopting a Monte Carlo modeling and tools has been developed in order to validate the proposed model accordingly with a multi scenario analysis. The performance of the system obtained by the adoption of the proposed analytical travel time models under different configurations of the warehousing system (shape and dimension of the classes, ABC curve) have been evaluated and discussed.