Least cost decision rules for transferring documents from primary to secondary storage are developed from a dynamic programing model of an information system. The program is constrained to provide for a minimum acceptable level of user benefits. Knowledge of the physical size of the primary storage area and the fraction of documents returned from secondary to primary storage in each decision period is required. Transfer, handling, and circulation costs are considered. Increase in the total size of the document collection is assumed to be an uncontrolled random process. (Author)