Consider a miniload AS/RS with two pick positions per aisle. It is assumed that the P/D station is located at the lower lefthand corner of the rack. Randomized storage is used.

The S/R machine travels at 400 fpm and 80 fpm in the horizontal and vertical directions, respectively. The total load handling time on a dual command trip is equal to 0.42 minute. The total storage area required is equal to 80,000 ft2. Last, the rack is required to have a shape factor of 0.90. Assuming that the pick time is constant (i.e., deterministic)

at 1.50 minutes per pick, determine the minimum number of aisles required to obtain a picker utilization of 100%.