Determination of automated storage/retrieval system size

This paper considers a problem of determining the automated storage/retrieval system size for which three different cases (including single and multiple types of Poisson arrival items, and single type of compound Poisson arrival items) are investigated. The problem is analyzed by investigating its equivalent finite capacity queueing model or its equivalent closed queueing network model for the long-run probability of the number of occupied storage spaces and the system blocking probability. These probabilities are then used to construct a computational algorithm to search for the optimal system size by introducing a management-set protection level. Illustrative numerical examples are presented.