A method of inventory control that includes as special cases most of the systems in practice. In this system, when an order is received for any item, it is used as a picking ticket, and duplicate copies, called replenishment orders, are sent back to all stages of production to initiate replenishment of stocks. Positive or negative orders, called base stock orders, are also used from time to time to adjust the level of the base stock of each item. In actual practice, replenishment orders are usually accumulated when they are issued and are released at regular intervals.