A study on multi-aisle system served by a single storage/retrieval machine

Multi-aisle S/R machine system (MASS) can substantially reduce high initial investment cost which is a major reason for the low popularity of AS/RS in manufacturing companies. The objective of this study is mainly related to the design aspects of MASS. With a travel time model developed, average travel time of S/R machine is determined. We propose rack-class-based storage assignment procedure and class selection procedure to find the minimum number of S/R machines required and identify the number of aisles each S/R machine serves. Example problems are solved to illustrate the procedures. The results show that MASS is effective in reducing initial installation cost, provided that the pallet demands are relatively low.