Performance of automated storage/retrieval systems with non-square-in-time racks and two-class storage

We determine the mean and variance of the single and dual command travel time for automated storage/retrieval systems with non-square-in-time racks and two-class storage. We present detailed numerical results of the travel time analysis for selected rack shape factors and skewness parameters, followed by some interesting observations for two-class storage. We then show, as an application example, how the mean and variance can be used to approximate or bound the miniload system throughput for non-square-in-time racks with two-class storage.