This paper focuses on warehouse optimization, in particular improving the overall performance of the Autonomous Vehicle Storage and Retrieval Systems. It analyzes it through coordination of the conveyor system as well as pick-up system with the rack storage system.
Such a warehouse system is first viewed as a Semi-Open Queuing Network (SOQN) which could be parameterized by arrival rates of new SKUs and out-store requests, storage, and retrieval service times of the rack system and pick-up pattern. Then the system is further analyzed by taking into account practical constraints including conveyors lengths, container unit dimensions, buffers capacities, and also transient effects including blocking on the conveyor system and unbalanced inventories.
With such considerations, a discrete event simulation model is developed to explore interactions between subsystems and system control policies. We use simulation to study the coordination between the rack system and the conveyor system in particular. We also conduct an experiment to compare the results of different coordination policies based on different throughput and pick-up assumptions. Recommendations are made for warehouse optimization and improving system performance under high throughput levels.