A perpetual inventory system enters each increase and each reduction of inventory to maintain up-to-date material records. These records, in either hard-copy or electronic from, constitute a subsidiary a subsidiary ledger controlled by the materials account in the general ledger. In addition to showing quantity and price for each kind of material received, issued, and on hand, the records commonly detail the account number, description or type of material, location, and maximum and minimum quantity to carry. New materials records are created and old ones are deleted as changes occur in thekinds f materials carried in stock. The record arrangement paralles the familiar debit, credit, and balance columns, but uses the headings received, Issued, and Inventory. ( Examples are shown in the discussion of materials costing methods in the appendix to this chapter.) additional columns can be added to record receiving report numbers and materials requisition numbers.