Magnetic tape utilization viewed as an inventory control problem

Abstract

Magnetic tapes are extensively used to store information. However, their low cost leads to problems in the efficient use of them as a storage media. There exists no scientific method to control the space utilization and the addition of new tapes to a tape library. A method is developed which provides control on the use of tapes, reduces the number of tapes in the library and minimizes the cost of storing information tapes. An inventory model is developed with the unused space on tapes as inventory. Replenishment can be done in one of two steps. The first deletes the expired datasets from the tapes and if the new inventory levels is less than S′, the least order level, a second step adds new tapes tapes to the library bringing the level up to S, the maximum order level. The level of inventory after replenishment can be anywhere between S′ and S′. The inventory model determines (1) When to delete expired datasets. (2) When to add new tapes to the library. No analytical solution is developed for the general cost equation for this model. However, an iterative procedure is offered which can be used to minimize the total cost of having unused space in the tape library.