Relocation and storage assignment strategy evaluation in a multiple-deep tier captive automated vehicle storage and retrieval system with undetermined retrieval sequence

This paper studies multiple-deep automated vehicle storage and retrieval systems (AVS/RSs) known for their high throughput performance flexibility. Compared to a single-deep system, AVS/RS has better space area utilisation. However, relocation cycle occurs, reducing the whenever another stock keeping unit (SKU) blocks retrieving SKU. The SKU sequence is undetermined, meaning that arrangement unknown, all SKUs have an equal probability of retrieval. In addition shuttle carrier, satellite attached carrier used access locations in multiple depths. A discrete event simulation with tier captive was developed. We focused on dual-command time assessment nine different assignment strategy combinations model. results study (i) random, (ii) depth-first (iii) nearest neighbour are examined benchmarked five case configurations same number locations. display fivefold- sixfold-deep AVS/RSs outperform fewer depths by utilising strategies.